Unicondylar osteoarticular allografts of the knee

Clinical course of grafted cartilage in osteoarticular frozen autografts for reconstruction after resection of malignant bone and soft-tissue tumor involving an epiphysis

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Frozen autograft of tumour-bearing bone using liquid nitrogen as a recycling autograft has various advantages.

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This paper is the first report focusing on the fate of grafted cartilage in recycled autograft after bone tumour excision.

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We found hemicondylar frozen autograft is promising reconstruction method.

There are several options for biological reconstruction after bone tumor resection. If the tumor invades an epiphysis, the reconstruction is far more complicated because there is no option to restore large joint cartilage using currently available medical techniques. Frozen autograft with liquid nitrogen has been used as recycled autologous bone graft and the purpose of the present study was to assess the outcome of grafted cartilage in osteoarticular frozen autografts used in the treatment of patients with bone and soft-tissue sarcoma. We have treated 27 patients with cases of bone tumor resection involving an epiphysis where frozen autografts were used for reconstruction. If the tumor was located in a limited part of the epiphysis, partial resection of the epiphysis was performed to preserve the healthy part of the cartilage in 4 cases. The survival of grafted frozen cartilage was assessed by X-ray imaging. The end point was defined as grade IV of the Kellgren and Lawrence osteoarthritis grading system and was recorded using the Kaplan–Meier method. In case of removal of grafted bone after the surgery, pathological findings were assessed by hematoxylin and eosin staining of sections of resected cartilage in available cases to observe the fate of grafted cartilage over time. The postoperative mean follow-up period was 94.0 months. Grade IV osteoarthritis occurred in 12 patients. All patients in the partial epiphyseal freezing group survived compared with only 1 patient in the total epiphyseal freezing group who had survived to the final follow up (p < 0.01). Resected specimens with grafted cartilage were examined histologically. A sample excised after 14 months had dead cartilage with empty lacunae and the surface of the cartilage had reactive fibrous tissue. Grafted cartilage of frozen osteoarticular autografts was worn out over time. However, intraepiphyseal resection preserving partial healthy cartilage resulted in excellent survival. This technique requires careful planning of the surgery but might be an alternative to megaprosthesis.

Complications following allograft reconstruction for primary bone tumors: Considerations for management

Introduction

The aim of this study was to investigate complication rates and types following allograft reconstruction and discuss unique considerations for management.

Methods

Seventy-four consecutive patients underwent large segment allograft reconstruction following resection of primary musculoskeletal tumors from 1991 to 2016. Mean patient age was 32 ± 20 years (range, 5-71 years). Minimum follow-up was 2 years unless patients were lost to disease prior. Mean follow-up was 105 months.

Results

Thirty-five patients had complications requiring subsequent surgery at a mean of 30 months (range, 1-146 months) post-operatively. Individual complication rates were 29%, 50%, and 42% for Allograft Prosthetic Composite, Intercalary, and Osteoarticular allograft reconstruction, respectively. Risk factors for complication included age less than 30 (OR 4.5; p = 0.002), male gender (OR 2.8; p = 0.031), chemotherapy (OR 4.4; p = 0.003), lower extremity disease (OR 3.4; p = 0.025). In patients with complications, limb-retention rate was 91% and mean MSTS scores were 23.6.

Conclusion

Despite considerable complication rates, management with a systematic approach results in successful outcomes with limb-retention greater than 90% and mean MSTS scores of 79%. In carefully selected patients, allografts provide a reliable method of reconstruction with treatable complications occurring at a mean of 30 months.

Is unicondylar osteoarticular allograft still a viable option for reconstructions around the knee?

BACKGROUND

Unicondylar osteoarticular allografts (UOAs) represent a possible technique for reconstructing massive bone defects around the knee when only one condyle is affected. The aim of this retrospective study is to evaluate the outcome of UOAs and describe the possible salvage procedures in case of graft failure.

METHODS

Twenty-five deep-frozen UOAs were implanted at Rizzoli Orthopedic Institute (Bologna, Italy). Twenty-two followed bone tumor resection, two cases were post-traumatic defects and one case followed UOA failure. Mean age at surgery was 33years (range: 15 to 63). Eighteen UOAs were in distal femur, seven in proximal tibia.

RESULTS

Three patients died (only one because of the tumor). One UOA was removed for chondrosarcoma relapse and one for allograft fracture. Mean overall survival with UOA failure as a primary endpoint was 129months (range 12 to 302), with differences in the femur (85%) and in the tibia (40%) at 150months. Six UOAs had to be converted into knee prostheses due to osteoarthritis after a mean follow-up of 146months. No complications were recorded in UOAs converted into knee prostheses after a mean three year follow-up. Fourteen patients with UOAs still in place at the last follow-up (mean 123months) were radiologically and functionally evaluated: no correlation was found between function and the degree of osteoarthritis.

CONCLUSIONS

In selected cases, UOAs offer good clinical results and postpone the need for knee prosthesis. Despite short-term encouraging results, longer-term follow-up is needed in order to evaluate the outcome of knee prosthesis after UOA.

Custom-made lateral femoral hemiarthroplasty for traumatic bone loss: A case report

We report the case of a 32-year-old male patient involved in a road traffic accident in which he sustained a grade II open supra- and intercondylar fracture of the left distal femur with substantial bone loss of the lateral femoral condyle and trochlea (AO classification type 33 C3). Normal knee function was no longer possible, as the patella was trapped within the bony defect. Existing reconstructive options such as unicondylar osteoarticular allograft, arthrodesis, and arthroplasty were considered. However, as all these techniques present significant disadvantages, particularly in young and active patients, a custom-made lateral hemiarthroplasty was designed and implanted as an alternative treatment. Follow-up at 24 months revealed an excellent, pain-free level of function and radiographs showed no signs of implant loosening or migration. This technique offers the most anatomical means of reconstruction with maximal preservation of the bone stock, thereby better facilitating any revisions that may be necessary in the future. This is an experimental technique reserved for rare indications, and currently has no long-term follow-up results associated with its use. Additional research is therefore needed before widespread adoption of this technique can take place.

Successful hemicondylar femoral allograft for traumatic bone loss: a paediatric case study with ten years of follow-up

The management of massive traumatic defects of the knee joint is challenging, especially in children. Massive osteoarticular allograft may be an option in this kind of traumatic bone loss. We report on the case of a male patient who (at the age of 15) suffered an open grade III condylar femoral joint fracture, with a massive bone defect and a Schatzker V tibial plateau fracture. Ten years after first-line treatment with massive osteoarticular allograft of the lateral femoral condyle, the patient's knee was capable of full extension and 90° flexion. The patient reached a point of being pain free for nine years before he subsequently developed some pain with lateral arthritis progression.

The principles and applications of fresh frozen allografts to bone and joint reconstruction

Fresh frozen allograft reconstruction has been used for a long time in massive bone loss in orthopedic surgery. Allografts have the advantage of being biologic reconstructions, which gives them durability. Despite a greater number of complications in the short term, after 5 years these stabilize with high rates of survival after 10 years. The rate of early complications and the need for careful management in the first years has led the orthopedic surgeon to the use of other options. However, the potential durability of this reconstruction makes this one of the best options for younger patients with high life expectancy.

Use of large osteochondral allografts in reconstruction of traumatic uncontained distal femoral defects

Large osteoarticular injuries with subchondral bone loss involving the knee in young active patients often result in significant morbidity and loss of normal joint function. A review of the current literature reveals that multiple surgical management options are currently employed, however there is no consensus on standard of care. Osteochondral allografting provides an attractive alternative treatment option for the repair of large articular defects of the knee.

METHODS

In this article we present the case of a young male who suffered traumatic intraarticular bone loss secondary to a grade IIIA distal femoral fracture and subsequently underwent reconstruction of his medial femoral condyle using a fresh-frozen osteochondral allograft.

RESULTS

We present the radiographic and functional outcome of this patient at two years post-operative. The range of motion of the knee was 0-130° and the patient's post-operative functional outcome was evaluated using the Knee injury and Osteoarthritis Outcome Score (KOOS), which was 76%.

CONCLUSIONS

While further research is required, the results of our case study concur with the current body of literature supporting the use of fresh-frozen osteochondral allograft as a reconstructive option for treating large traumatic intraarticular lesions involving the distal femur.

Surgical technique: Computer-generated custom jigs improve accuracy of wide resection of bone tumors

BACKGROUND

Manual techniques of reproducing a preoperative plan for primary bone tumor resection using rudimentary devices and imprecise localization techniques can result in compromised margins or unnecessary removal of unaffected tissue. We examined whether a novel technique using computer-generated custom jigs more accurately reproduces a preoperative resection plan than a standard manual technique.

DESCRIPTION OF TECHNIQUE

Using CT images and advanced imaging, reverse engineering, and computer-assisted design software, custom jigs were designed to precisely conform to a specific location on the surface of partially skeletonized cadaveric femurs. The jigs were used to perform a hemimetaphyseal resection.

METHODS

We performed CT scans on six matched pairs of cadaveric femurs. Based on a primary bone sarcoma model, a joint-sparing, hemimetaphyseal wide resection was precisely outlined on each femur. For each pair, the resection was performed using the standard manual technique on one specimen and the custom jig-assisted technique on the other. Superimposition of preoperative and postresection images enabled quantitative analysis of resection accuracy.

RESULTS

The mean maximum deviation from the preoperative plan was 9.0 mm for the manual group and 2.0 mm for the custom-jig group. The percentages of times the maximum deviation was greater than 3 mm and greater than 4 mm was 100% and 72% for the manual group and 5.6% and 0.0% for the custom-jig group, respectively.

CONCLUSIONS

Our findings suggest that custom-jig technology substantially improves the accuracy of primary bone tumor resection, enabling a surgeon to reproduce a given preoperative plan reliably and consistently.

Haptic robot-assisted surgery improves accuracy of wide resection of bone tumors: a pilot study

BACKGROUND

Accurate reproduction of the preoperative plan at the time of surgery is critical for wide resection of primary bone tumors. Robotic technology can potentially help the surgeon reproduce a given preoperative plan, but yielding control of cutting instruments to a robot introduces potentially serious complications. We developed a novel passive ("haptics") robot-assisted resection technique for primary bone sarcomas that takes advantage of robotic accuracy while still leaving control of the cutting instrument in the hands of the surgeon.

QUESTIONS/PURPOSES

We asked whether this technique would enable a preoperative resection plan to be reproduced more accurately than a standard manual technique.

METHODS

A joint-sparing hemimetaphyseal resection was precisely outlined on the three-dimensionally reconstructed image of a representative Sawbones femur. The indicated resection was performed on 12 Sawbones specimens using the standard manual technique on six specimens and the haptic robotic technique on six specimens. Postresection images were quantitatively analyzed to determine the accuracy of the resections compared to the preoperative plan, which included measuring the maximum linear deviation of the cuts from the preoperative plan and the angular deviation of the resection planes from the target planes.

RESULTS

Compared with the manual technique, the robotic technique resulted in a mean improvement of 7.8 mm of maximum linear deviation from the preoperative plan and 7.9° improvement in pitch and 4.6° improvement in roll for the angular deviation from the target planes.

CONCLUSIONS

The haptic robot-assisted technique improved the accuracy of simulated wide resections of bone tumors compared with manual techniques.

CLINICAL RELEVANCE

Haptic robot-assisted technology has the potential to enhance primary bone tumor resection. Further bench and clinical studies, including comparisons with recently introduced computer navigation technology, are warranted.

Surgical technique: Unicondylar osteoallograft prosthesis composite in tumor limb salvage surgery

BACKGROUND

After resecting tumors confined to one femoral condyle, a unicondylar osteoarticular allograft can be used for reconstruction without sacrificing the uninvolved condyle. However, unicondylar osteoarticular allografts have been associated with a high rate of joint degeneration. We describe a unicondylar osteoallograft prosthesis composite reconstruction replacing only one side of the joint to reduce compartment degeneration and avoid contamination of the tibia, but the survival, function, and complications of a unicondylar osteoallograft prosthesis composite are unclear.

DESCRIPTION OF TECHNIQUE

We located a bone resection plane intraoperatively as planned before surgery using a computer-assisted navigation system. The tumor then was removed en bloc and the unicondylar defect filled with a size-matched allogeneic unicondyle. The allograft cartilage was removed. Thereafter, the condyle of the femoral component was resurfaced with a unicompartmental knee prosthesis to form a unicondylar osteoallograft prosthesis composite, however the tibia was left undisturbed. Navigation allowed precise apposition between the unicondylar osteoallograft prosthesis composite and host bone to ensure mechanical alignment and congruency of the joint surface before fixation with a plate.

METHODS

We retrospectively reviewed 12 patients who underwent unicondylar osteoallograft prosthesis composite reconstructions after unicondylar resection for tumors. One patient died from tumor-related causes without unicondylar osteoallograft prosthesis composite failure after 18 months. We observed the survival rate of unicondylar osteoallograft prosthesis composite reconstruction and related complications. Function and radiographs also were documented according to the Musculoskeletal Tumor Society (MSTS) functional scoring system and the International Society of Limb Salvage radiographic scoring system. The minimum followup was 8 months (median, 37 months; range, 8-65 months).

RESULTS

At last followup, 10 of the 12 unicondylar osteoallograft prosthesis composite reconstructions were still in place. Three reconstructions failed owing to two local recurrences (both treated with amputation) and there was one infection (treated with revision and maintenance of the implant at last followup). The average MSTS functional score at last followup was 27 points and the radiographic score 91%.

CONCLUSIONS

Our observations suggest unicondylar osteoallograft prosthesis composite reconstruction might be a reliable technique with relatively few major complications and at least short-term maintenance of the tibial cartilage.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Custom-made lateral femoral condyle replacement for traumatic bone loss: a case report

We report the case of a 24 year-old patient who underwent a novel treatment for a lateral femoral condyle fracture. The fracture was associated with extensive joint line depression and not considered suitable for conventional fixation techniques. Existing reconstructive options for such situations include unicondylar osteoarticular allograft, arthrodesis and arthroplasty. However, these techniques all present significant disadvantages, particularly in the management of active patients. We report our medium-term results following reconstruction using a custom-made lateral femoral condyle hemiarthroplasty replacement. Follow-up at 48 months revealed an excellent, pain-free level of function, with an Oxford Knee Score of 46/48, a Knee Society knee score of 87/100 and a functional score of 100/100. Radiographs demonstrated no evidence of prosthesis loosening or migration and no erosion of the lateral tibial plateau. The technique allows preservation of the remaining normal joint surface of the femur that may promote earlier and better restoration of function. Furthermore, the isolated condyle hemi-replacement maximises bone preservation, facilitating future anticipated revisions. The procedure presents an attractive alternative to other surgical options and their attendant problems. Further investigation into this technique is required before widespread adoption, though such studies will be compromised by the relative rarity of patients in whom the technique is indicated.

The use of unicondylar osteoarticular allografts in reconstructions around the knee

Unicondylar osteoarticular allografts (UOA) of the knee are mainly used after bone tumour resections for benign aggressive tumours or small malignant tumours with clearly defined margins. They are also used less often in large posttraumatic condylar defects. Between 1989 and 2004, 12 deep-frozen UOA reconstructions (in 11 patients) were performed at our Institute. The diagnosis was chondrosarcoma in four cases, giant cell tumour in three, osteosarcoma in three, posttraumatic defect in one, and one failed UOA. The involved site was the medial femoral condyle in six cases, the lateral femoral condyle in three, the medial side of the tibial plateau in two, and the lateral in one case. One allograft was removed after 29 months because of an intra-articular displaced fracture, and substituted with a new UOA. One patient died of metastatic disease at 24 months. We report the functional and radiographical outcome of the remaining 10 UOAs with a minimum follow-up of 4 years (average 11 years). Two of the 10 patients had excellent results, five were good and three were fair. Radiographically, five patients had "mild" and five had "severe" degenerative changes. One patient with severe degenerative changes had pain and stiffness, therefore the UOA was converted into a prosthesis allograft composite, using a conventional total knee prosthesis. In selected cases of distal femoral and proximal tibial tumours, UOA reconstructions give good functional outcomes with relatively few major complications.