Chapter 36B - Atlas of Limb Prosthetics: Surgical, Prosthetic, and Rehabilitation Principles
Van Nes Rotation-Plasty in Tumor Surgery
Ivan Krajbich, M.D. F.R.C.S.(C)
J. Dietrich Bochmann, C.P.O.(C.), F.C.B.C.
The standard treatment for malignant tumors of the limbs has for decades, if not centuries, been an amputation. In the lower limb with the tumor usually situated around the knee, this usually meant transfemoral (above-knee) amputation or a hip disarticulation and, in more proximal lesions, a transpelvic amputation (hemipelvectomy). With the advent of modern chemotherapy, new imaging techniques, and consequent improved survival rates came a renewed interest in improved surgical techniques to avoid ablative surgery. Thus in the last 15 years or so the surgical science of limb salvage surgery came into being. From the pioneering work of Campanacci, Enneking, and others a number of surgical techniques have been developed that are aimed at preserving limbs. The biggest challenge to the surgeons engaged in this practice has been the problem of the loss of the knee joint in a young patient. The early efforts tried to avoid this problem by creating a knee arthrodesis, i.e., replacing the excised knee segment with autograft or allograft bone. Although this technique is still quite useful in many patients, it has very significant drawbacks, particularly for a person of relatively tall stature or a person inclined toward physical and athletic activity. In addition, the technique is impractical in young children due to the necessary resection of growth plates around the knee and the resultant leg length discrepancy.
The newer technique of limb salvage using a tumor replacement endoprosthesis is currently quite popular; however, it also has significant limitations. A sufficient soft-tissue-muscle envelope must be preservable to stabilize and motorize the new endoprosthetic knee. It must be understood that this metallic-plastic implant has a finite life span due to material fatigue. The metal-bone interface also has the potential for long-term problems due to the shear stresses secondary to different Youngs moduli of elasticity of the two dissimilar, yet intimately apposed materials, such as bone and a metal or plastic. Again, in young children, the loss of the growth centers, with resultant leg length discrepancy, is a significant problem in using an endoprosthesis in this age group. This is in spite of efforts to produce a satisfactory version of a "growing endoprosthesis."
The technique that appears to address at least some of the problems associated with the above-described procedures is a modified Van Nes rotation-plasty. This technique replaces the excised knee with a biological joint, the patient's own ipsilateral ankle, which is rotated 180 degrees and fixed at the level of the opposite knee. The consequent absence of the lower portion of the leg and foot is then replaced by an external prosthesis. It is hoped that the patients function will approximate the function of a transtibial (below-knee) amputee with a fully functional "knee joint."
The technique was first adapted to treat osteosarcoma of the distal third of the femur by Saltzer and Kotz in Vienna in late 1970s. The rotation-plasty itself was first described by Borggreve in Germany in 1930 for a patient whose knee was destroyed by tuberculosis. The technique was later made popular in the English literature by Van Nes in 1950. He used the technique in children and young adults affected by congenital limb deficiency. This use of the rotation-plasty in children with proximal femoral focal deficiency (PFFD) gained popularity in a number of centers. This familiarity with the operation and availability of both surgical and prosthetic expertise allowed relatively smooth adoption of this procedure as a limb salvage technique in North America.
PRINCIPLES AND INDICATIONS
The early efforts in limb salvage surgery were hampered by a relatively high complication rate. In particular, this included the high local recurrence rate, wound breakdowns, and infection rates, combined with sometimes-questionable functional results that tempered the early surgical enthusiasm. It was not until Enneking's pioneering work in classification of musculoskeletal neoplasms and their surgical resection margins that some sound principles were introduced into tumor surgery practice. Adequate surgical margins together with the realization of the importance of soft-tissue coverage plus objective evaluation of the functional results allow us at the present time to employ a rational approach to sarcoma surgery that is based on several basic principles:
1.Margins of the resection must be adequate to the tumor stage, i.e., a radical or wide margin as defined by Enneking is the only admissible margin in stage IIA or IIB tumors.
- The targeted margin must be achieved all through the surgical field and planes of resection. A single violation invalidates or jeopardizes the whole effort.
- Adequate nerve and blood supply of the distal part of the limb must be preservable. A poorly perfused, insensitive, paralyzed limb is a poor substitute for an appropriate amputation with a functional prosthesis.
- Muscle and skin coverage must be sufficient for at least a two-layer closure of the soft-tissue envelope. This is particularly important where foreign materials such as metal endoprostheses or allograft bone transplants are employed. In rotation-plasty careful planning of the procedure is needed to ensure viability of the skin flaps and the distal part of the limb. This is one of the most important principles and yet the most difficult one to heed. It is sometimes very tempting to perform a technically demanding limb salvage surgery in the face of a borderline or inadequate soft-tissue coverage. One only has to realize that every minor wound breakdown or superficial infection in the face of immunosuppression from ongoing chemotherapy, compounded by the presence of underlying foreign material, can quickly escalate into a disaster. Even at the best of times it can lead to at least a delay in reemployment of the chemotherapy treatment, thus potentially jeopardizing a patients survival. We have found that in borderline cases, it is better to utilize soft-tissue flap transfers to improve local coverage or to employ another procedure that is less demanding on the availability of healthy local tissue such as a rotation-plasty.
- The surgical procedure performed should be carefully selected and discussed with the patient and his family to carefully match the patients physical, functional, physiologic, psychological, and life-style makeup to the planned operation.
Principles Specific to Rotation-plasty
Rotation-plasty is a technique where the ankle and foot replace the knee joint; thus, it can potentially be used in any of the lesions of the lower limb provided that the ankle and foot are disease free, their blood and nerve supply can be maintained, and adequate muscle can be found to power it. Not surprisingly then, the technique, which was originally described for lesions of the distal end of the femur, has been modified for use in lesions of the proximal parts of the femur and the tibia. The technique for all those modifications follow the same principles:
- The ankle and foot must be disease free.
- Adequate nerve supply to the foot and ankle must be preservable.
- Adequate blood supply to the foot and ankle must be either preservable or restorable after resection of a segment of a disease-involved vessel.
- It must be possible to restore muscle power to the ankle joint.
- Large amounts of tissue can be resected, thus making this procedure possible even in cases where there are quite extensive and large lesions (Fig 36B-1.).
The modified Van Nes rotation-plasty is a versatile procedure that can be used for virtually every lesion involving the femur or proximal third of the tibia. However, its primary advantage is the fact that it can be safely performed even in situations where other forms of limb salvage are not possible or are functionally inadequate. Specifically, Van Nes rotation-plasty can be performed in the following situations:
- Lesions of the distal or proximal thirds of the femur and proximal end of the tibia in young children where the expected remaining growth in the opposite healthy leg is greater than 10 cm.
- Cases where the size of the tumor necessitates removal of so much of the bone or soft-tissue stock as to make any other form of limb salvage impractical.
- Lesions where blood supply to the distal part of the limb is compromised by the tumor and can be safely re-established only by segmental resection of the major blood vessel and reanastomosed.
- Children and young adults where function and physical or athletic performance is of major importance and subjectively outweighs the importance of cosmesis and the necessity of a prosthesis.
- Cases of failed reconstruction due to infection in an allograft reconstruction or local recurrence in endoprosthesis replacement, provided that the nerve supply can be safely preserved.
- Cases of late, unacceptable sequelae of previous, more conventional reconstructions, for example, late unmanageable leg length discrepancy or long-term failure of endoprosthetic components with corresponding loss of bone stock.
Careful preoperative planning is an important aspect of the Van Nes rotation-plasty technique. This is particularly so in the cases of skeletally immature children where the expected remaining growth has to be taken into consideration. The goal of the surgical procedure is to end up with a thigh segment that will be of the same length as the opposite thigh at the end of skeletal growth. Ideally, at skeletal maturity the distal aspect of the os calcis in the Van Nes rotation-plasty thigh will be at the level of the distal aspect of the femoral condyles of the normal limb. This gives the patient equal knee levels in both the standing and sitting positions.
In the preoperative planning for a young child we have to take into account the differential growth in the rotation-plasty thigh (contributed to by the proximal femoral epiphysis, by the distal tibial epiphysis, and by the growth of the calcaneotalar unit) and the normal thigh (contributed to by the proximal femoral and distal femoral epiphyses).
Mosely's straight-line graph for leg length growth and a simple calculation allows for a determination of the appropriate length of the Van Nes thigh during the surgery. Each patient should have full-length leg ortho-grams taken preoperatively together with a lateral radiograph of the foot and a determination of skeletal age (Fig 36B-2.,A and B).
In the case of skeletally mature individuals, the length of the new "thigh" needs to correspond exactly to the opposite member and is made up of a femoral fragment, tibial fragment, and the calcaneotalar unit. A decision has to be made preoperatively based on the staging studies (magnetic resonance imaging [MRI] or contrast-injected computed tomography [CT]) (Fig 36B-3.,A and B) regarding the need for vascular resection. In most cases the vessels can be preserved; however, if the vessels are either involved by the tumor or are within the reactive zone of the tumor, it is safer to resect them together with the tumor and reanastomose the transected ends.
Distal Femoral Lesions
Rotation-plasty in tumor surgery was originally described for lesions of the distal part of the femur and is still most widely used in this situation (Fig 36B-4.). For the procedure the whole lower limb is prepared and draped free (Fig 36B-5.). Incisions are marked on the skin. We usually employ a circular circumferential incision proximally and an oval circumferential incision dis-tally to compensate for the difference in the diameter of the leg distally and proximally. The two circumferential incisions are connected by longitudinal incisions medially and laterally to facilitate the dissection of the neurovascular bundles. The sciatic nerve needs to be isolated along the entire length of the surgical wound. The femoral vessels are either dissected free along the entire length or isolated proximally and distally when the vessels are involved by tumor. Quadriceps, hamstrings, and adductors are then transected at the level of the planned bone transection. Distally, gastrocnemius heads are divided 2.5 cm. distal to their origin on the back of the femoral condyles. Pes anserinus tendons are divided near their insertion on the proximal end of the tibia. Osteotomies of the tibia and femur are completed, and in the case of vessel resection, these are now cross-clamped and divided. The resected specimen, which includes the middle and distal portion of the femur, knee joint, and the proximal portion of the tibia, together with their soft tissue and skin covers, is then removed and submitted to pathology for assessment of margins and degree of tumor necrosis (Fig 36B-6.).
Osteosynthesis using an Arbeitsgemeinschaft fur Os-teosynthesefragen (AO, Association for Osteosynthesis) (AO) plate or intramedullary fixation is carried out between the proximal ends of the femur and tibia, with the distal fragment being turned 180 degrees (Fig 36B-7.). Following fixation the foot points directly posteriorly. In the case of vessel resection, these are now reanastomosed to re-establish circulation to the distal part of the limb. The muscles are then reattached by suturing the proximal quadriceps to the heads of gastrocnemius and the hamstrings and adductor to the fascia of the anterior and lateral compartments of the leg, respectively. Skin flaps are then trimmed and closed (Fig 36B-8.).
Proximal Tibial Lesions
The technique for the procedure in cases of proximal tibial lesions uses similar skin incisions to the ones described above, except that they are based over the distal ends of the femur and tibia, respectively (Fig 36B-9.,A and B).
The sartorius, gracilis, and hamstring muscles are divided approximately 5 cm proximal to their insertions and labeled. The medial and lateral heads of the gastrocnemius are detached from their origins on the distal part of the femur. This facilitates exposure of the neurovascular bundle in the proximal part of the popliteal fossa. Vessels and nerves are then sacrificed as necessary or dissected free and preserved as planned preop-eratively. The anterior tibial artery almost always has to be divided at its origin, as does the deep branch of the peroneal nerve. The structures to be sacrificed are then divided distally.
The tendons that control the ankle and foot are identified, labeled, and divided. Bones are osteotomized and the specimen removed. Osteosynthesis is carried out (Fig 36B-10.), and the vessels are reanastomosed where required. Finally, the thigh muscles are attached to the tendons of the ankle and foot: the biceps femoris and semimembranosus to the tibialis anterior tendon, the semitendinosus to the extensor hallucis longus and extensor digitorum longus tendons, and the gracilis and sartorius to the peronei. The quadriceps tendon is attached to the Achilles tendon and the vastus lateralis to the tendon of the tibialis posterior. The tension on these tendons should balance the foot in a neutral position (Fig 36B-11.,A and B). Skin edges are trimmed as needed and the wound closed, care being taken not to place the skin under undue tension. The limb is then immobilized in a neutral position in a well-padded plaster cast.
Proximal Femoral Lesions
In lesions of the proximal end of the femur and around the hip joint, the extent of the proximal dissection will vary depending on the extent of the tumor involvement (Fig 36B-12.). It can be as little as an internal hip disarticulation or as extensive as almost complete internal transpelvic amputation. The sciatic nerve must be preserved, but the femoral nerve can be sacrificed if needed, and a segment of the femoral vessels can also be resected and later reanastomosed. An attempt is made to preserve as much of the iliopsoas and gluteus maximus as possible and to later reattach them to the distal stump of the hamstrings and quadriceps, respectively. The rest of the thigh musculature is removed together with the tumor. Distally the femur is transected above the knee, with the exact length being determined by the necessary extent of the proximal excision. It should be such that after the femur-to-pelvis osteosynthesis, the level of the rotated knee joint is at the same level as the opposite hip. Osteosynthesis of the distal part of the femur is either to the side of the pelvis just cranial to the acetabulum in the case of a disarticulation or to the stump of the ilium in the case of a partial transpelvic amputation. The osteosynthesis is carried out with the distal fragment rotated 180 degrees, thus converting knee flexion into a new "hip" flexion and knee extension into "hip" extension. Because the knee joint is essentially a one-plane hinge joint rather than a multiplane ball and socket, joint abduction and adduction and any rotation are lost (Fig 36B-13.). The rotated ankle again functions as a knee.
Our experience is based on 27 patients, children, adolescents, and young adults, all with the diagnosis of osteogenic sarcoma. The tumor was in the distal portion of the femur in 18 patients, in the proximal part of the tibia in 8, and in the proximal part of the femur in 1. Ten patients required resection of the main vessels with anastomotic repair because of tumor involvement. The procedure was successfully completed in all cases, and there were no intraoperative complications. Postoperatively we had one deep infection requiring debridement, but this had no influence on the eventual outcome. There was one significant wound breakdown requiring debridement and long-term management. This patient appeared to have generalized poor tissue healing because he experienced similar breakdown of a thoracotomy wound for resection of metastatic deposits. His function could not be fully evaluated since he died of metastatic disease 8 months after the original surgery and was in poor physical condition for virtually the whole postoperative interval as chemotherapy and repeat thoracotomies took their toll. Six patients had minor delayed healing that responded well to local dressings and did not interfere with either chemotherapy or prosthetic fitting. These were most likely explained by the early reinstitution of chemotherapy. More importantly, there have been no local recurrences, no neurovascular compromises, and no delayed or nonunions.
Of the 27 patients, 5 have died, 4 of metastatic disease and 1 from a second malignancy (leukemia).
The rest of the patients are alive and well with no evidence of disease. All patients with at least 6 months' follow-up became excellent prosthetic users with range of motion in their ankle-knee of at least 70 degrees, with the exception of the one patient with wound
breakdown and metastatic disease described above. Function in these patients is approaching the desired and planned-for transtibial amputee level (Fig 36B-14.,A-D).
There were no long-term complications related to the rotation-plasty, i.e., no late derotation or psychological decompensation (two frequently mentioned objections to this procedure). Several of our patients underwent energy consumption analysis during gait training and demonstrated significantly better functional results over a comparable group of patients with either transfemoral amputation or knee arthrodesis. Virtually all of our patients participate actively in sports and athletics, many of them competing against their normal-bodied peers. Our patients run; play soccer, baseball, and badminton; participate in karate; skate; ski; and ride bicycles among many other activities.
To permit ultimate mechanical advantage in the construction of the prosthesis the foot should be rotated precisely 180 degrees, and the ankle joint should be at a height equal to the level of the center of the knee of the sound leg. The range of motion of the ankle postoperatively varies with the site of intervention.
The removal of a tumor from the femur only slightly affects the muscle motors that drive the ankle and foot. Full ankle range of motion can be realized early after the operation. The prosthetist is required to reset the foot socket alignment only minimally to utilize the additional range of motion gained during the first few weeks of walking with the prosthesis.
The removal of a tumor from the proximal portion of the tibia or fibula temporarily impairs the function of the muscle motors driving the ankle and foot. Frequent resetting of the foot socket into plantar flexion is necessary.
Therapy and an exercise program to stretch the muscles that are now activating the ankle is of utmost importance. Walking with the prosthesis contributes to improved mobility and strength. The prosthetist should delay final completion of the prosthesis until a satisfactory range of ankle motion is realized.
During the casting procedure the patient should be standing with the limb in a relaxed vertical position and the foot in the utmost plantar flexion (Fig 36B-15.). Plaster wrap is applied over a tailored cotton stockinette. The wrap covers the foot and extends proximal to about 7.5 cm. below the ischial tuberosity. The ankle and foot are manipulated into full plantigrade position, and the weight-bearing areas, the bottom of the heel, the shelf for the plantar ligament, and the sole of the foot are hand-molded to achieve an intimate interface. When the plaster is set to moderately bear weight, the knee center level of the prostheses is measured. In order to achieve a precise reading, spacers are placed on the floor and are built up to reach the distal end of the plaster wrap. With minimal weight in the cast the patient stands on the spacers. The anterosuperior iliac spines must be level, and the spacers are adjusted accordingly. Plumb lines are marked on the wrap anteriorly to record the abduction/adduction angle and laterally to record the flexion/extension angle of the hip. When filling the cast with plaster later, the holding mandrel is set in parallel with the plumb lines, and thus the recorded angles are transferred to the positive. Next the level and external rotation of the prosthetic knee axis is located and marked on the wrap. The axis is positioned horizontally at a level slightly distal to the anatomic medial malleolus and slightly proximal to the anatomic lateral malleolus. It must be approximately 1.3 cm. posterior to the actual rotation of the ankle. It is of utmost importance to align the knee axis close to 5 degrees of external rotation in order to achieve a satisfactory swing phase during gait regardless of the physiologic alignment of the ankle. Because of the ankle's capability to move in multiple planes, it readily accepts the superimposed forces of the prosthetic knee hinges.
The cast is removed from the patient and filled with plaster of paris. After the plaster is set, the knee axis location marks are transferred by piercing the plaster wrap at these points with a scriber.
During modifications of the positive mold, generous build-ups are applied to the toes. The malleoli are moderately covered with an ?-in. layer of plaster. The areas below the heel and the plantar ligament are reduced and modified to form the weight-bearing shelf. A thumb tack is pressed into place on the medial and lateral knee axis marking. The protruding head of the tack is easily detected after socket lamination and serves to identify the knee hinge location.
The foot socket is laminated with conventional fabrication procedures. Additional glass reinforcement to strengthen the side hinge mounting area is recommended. The leather corset is stretched around the mold and stapled in place.
The cast-holding mandrel with the positive mold and the fabrication is suspended in a transfer jig and adjusted to permit accurate fixation of the knee hinges to be centered at the protrusions created by the tacks in the mold. The hinges are contoured to match the outline of the foot socket and the corset. The lower units of the side hinges are cemented to the foot socket with acrylic resin and glass overlay. During the curing of the resin the hinges are held parallel and at equal level by the hinge alignment fixture module of the transfer jig. The upper side hinges are marked on the corset for future reference.
The foot socket is cemented to a wood base and mounted onto a gait alignment coupling, and the prosthetic foot is attached. The positive mold is removed, and the foot socket is trimmed to ease entrance for the foot. The side hinges are assembled, and the corset is fastened according to the reference marking. The side hinges and corset ensure lateral stability, and the extension stop prevents excessive stretching of the ankle.
The prosthesis is suspended by a heel strap, an instep strap, and the intimate fit of the side hinges and corset. The heel strap attaches on the medial side of the foot socket anterior to the lower side hinge and arches above the heel to a tuck loop on the lateral side of the foot socket. Tension is adjustable via the Velcro closure. The area over the Achilles tendon is padded with Plastazote. The instep strap spans the posterior opening of the foot socket. Its purpose is twofold. In addition to providing suspension, it exerts the necessary force to the instep of the foot to stabilize the heel on the heel cup shelf (Fig 36B-16.). The dynamic alignment procedure follows the conventional technique described for transtibial prostheses with side joints and a corset (Fig 36B-17.).
The prostheses may be completed in the endoskele-tal or exoskeletal configuration (Fig 36B-18.). Full-length cosmetic foam fairings are preferred by most female patients.
The selection of a suitable prosthetic foot depends on the level of activity of the individual. Dynamic-response feet perform well and are popular with athletes.
Recent experiments with a soft and pliable socket limb interface to improve comfort show promise, and our work in this area will continue.
Limb salvage in skeletally immature individuals presents a number of challenges. The most important of these is the high functional demand of the lower limbs in physically active youngsters and the problem of loss of the major growth centers around the knee. Both of these factors make standard limb salvage operations such as knee resection, arthrodesis, or internal knee arthroplasty less than optimal options because the child faces significant limitation in physical activities and leg length discrepancy. The Van Nes rotation-plasty provides a partial answer to these problems. The child can approach the activity level of a transtibial amputee and participate in a number of sporting activities. Modern, expert prosthetic fitting using a dynamic-response prosthetic foot allows a relatively high degree of athletic participation.
As far as the leg length discrepancy is concerned, careful preoperative planning using predicted normal thigh length at skeletal maturity and predicted expected growth in the Van Nes thigh allows the surgical procedure to be performed so that the patient's thighs will be of equal lengths at skeletal maturity. Any minor discrepancy can be adjusted by the prosthetic component.
Another advantage of the Van Nes rotation-plasty is the low complication rate. It is a dependable procedure with a dependable result. It can be used in cases in which other alternatives are not feasible, such as in cases of large tumors, in tumors involving skin, in cases with poorly placed biopsy incisions, or in cases in which other reconstructions have failed.
The disadvantages of an exoprosthesis and cosmesis are well known. In this study group, cosmesis did not seem to cause a problem. Most patients were well aware of the appearance and function of the rotation-plasty before surgery. We now have an established network of patients who have had rotation-plasty, so every new patient who was a candidate for Van Nes rotation-plasty had an opportunity to meet a patient from the network. However, objective psychological evaluation may be a better indicator of this parameter. Use of the external prosthesis is, of course, inevitable in a procedure that converts a potential transfemoral amputee to a functional transtibial amputee.
The Van Nes rotation-plasty is a worthwhile alternative for skeletally immature individuals, for patients who place function ahead of cosmesis and in cases in which the transfemoral amputation is the only other alternative.
Bochmann D: Prosthetic devices for the management of proximal femoral focal deficiency. Orthop Prosthet 1980; 12:4.
Borggreve J: Knieglenksersaty durch das in der Beinlang-achse um 18 Grad gedrehte Fussgelenk. Arch Orthop Un-fallchir 1930; 28:175.
Campanacci M, Bacci G, Pagani P, et al: Multiple-drug chemotherapy for the primary treatment of osteosarcoma of the extremities. J Bone Joint Surg [Br] 1980; 62:93-101.
Campanacci M, Coster P: Total resection of distal femur or proximal tibia for bone tumors. Autogenous bone grafts and arthrodesis in twenty-six cases. J Bone Joint Surg [Br] 1979; 61:455.
DeBari A, Krajbich, JI: Modified Van Nes rotationplasty for osteosarcoma of the proximal tibia in children. J Bone Joint Surg [Br] 1990; 72:1065.
DeBari A, Krajbich JI, Langer F: Large allografts in reconstruction procedures in children. Presented at the Pediatric Orthopaedic Society of North America Annual Meeting, Colorado Springs, May 8, 1988.
Enneking WF, Shirley PD: Besection-arthrodesis for malignant and potentially malignant lesions about the knee using an intramedullary rod and local bone grafts. J Bone Joint Surg [Am] 1977; 59:223.
Enneking WF, Spanier SS, Goodman MA: Current concepts review. The surgical staging of muscoloskeletal sarcoma. J Bone Joint Surg [Am] 1980; 62:1027-1030.
Enneking WF, Springfield DS, Present DA: Functional evaluation of resection-arthrodesis for lesions about the knee, in Enneking WF (ed): Limb Salvage in Musculoskeletal Oncology. New York, Churchill Livingstone Inc, 1987, p 389.
Fixsen JA: Rotation-plasty (editorial). J Bone Joint Surg [Br] 1983; 65:529-630.
Hall JE, Bochmann D: The surgical and prosthetic management of proximal femoral focal deficiency, in Proximal Femoral Focal Deficiency: A Congenital Anomaly. New York, National Academy of Sciences, 1969.
Jacobs PA: Limb salvage and rotationplasty for osteosarcoma in children. Clin Orthop 1984; 188:217.
Jaffe KA, Gebhardt MC, Mankin HJ: Massive bone allografts for tumor and other reconstructions in children. Presented at the Association of American Orthopaedic Surgeons 56th Annual Meeting, Las Vegas, Feb 11, 1989.
Knahr K, Kristen H, Bitschl P, et al: Prosthetic management and functional evaluation of patients with resection of the distal femur and rotationplasty. Orthopedics 1987; 10:1241.
Kostuik JP, Gillespie B, Hall JE, et al: Van Nes rotational osteotomy for treatment of proximal femoral focal deficiency and congenital short femur. J Bone Joint Surg [Am] 1975; 57:1039.
Kotz B, Salzer M: Botation-plasty for childhood osteosarcoma of the distal part of the femur. J Bone Joint Surg [Am] 1982; 64:959.
Krajbich JI: Modified Van Nes rotationplasty in the treatment of malignant neoplasms in the lower extremities of children. Clin Orthop 1991; 262:74-77.
Krajbich JI: The method of predicting the level of the knee in the modified Van Nes rotationplasty. Presented at the Pediatric Orthopaedic Society of North America Annual Meeting, Toronto, May 19, 1987.
Krajbich JI, Carroll NC: Van Nes rotationplasty with segmental limb resection. Clin Orthop 1990; 256:7-13.
Mankin HJ, Doppelt SH, Sullivan TB, et al: Osteoarticular and intercalary allograft transplantation in the management of malignant tumors of bone. Cancer 1980; 50:613.
McClenaghan BA, Krajbich JI, Pirone A, et al: Comparative assessment of gait after limb-salvage procedures. J Bone Joint Surg [Am] 1989; 71:1178.
McDonald JD, Capanna B, Biagini B, et al: Complications following limb-sparing surgery of the extremities. Presented at the American Association of Orthopedic Surgeons 56th Annual Meeting, Las Vegas, Feb 11, 1989.
Bosen G, Murphy ML, Huvos AG, et al: Chemotherapy, en bloc resection, and prosthetic bone replacement in the treatment of osteogenic sarcoma. Cancer 1976; 37:1-11.
Sim FH, Chao EYS: Prosthetic replacement of the knee and a large segment of the femur or tibia. J Bone Joint Surg [Am] 1979; 61:887.
Simon MA, Aschliman MA, Thomas N, et al: Limb-salvage treatment versus amputation for osteosarcoma of the distal end of the femur. J Bone Joint Surg [Am] 1986; 68:1331-1337.
Waters BL, Perry J, Antonelli D, et al: Energy cost of walking of amputees; the influence of level of amputation. J Bone Joint Surg [Am] 1976; 58:42-46.
Watts HG: Introduction to resection of musculoskeletal sarcoma. Clin Orthop 1980; 153:31-38.
Winkelmann W: Botationplasty for malignant tumors of the femur and tibia. Proceedings of the International Symposium on Limb Salvage in Musculoskeletal Oncology, Kyoto, Japan, 1987. New York, Springer Publishing Co Inc, 1988, p 153.
Winkelmann WW: Hip rotationplasty for malignant tumors of the proximal part of the femur. J Bone Joint Surg [Am] 1986; 68:362-369.
Chapter 36B - Atlas of Limb Prosthetics: Surgical, Prosthetic, and Rehabilitation Principles