Clinical Outcomes After Definitive Treatment of Soft Tissue Sarcoma of the Hand: A Retrospective Cohort Study of 109 Patients.

PURPOSE: The purpose of this study was to provide updated data on oncologic outcomes following definitive surgical treatment of soft tissue sarcoma of the hand in a cohort of 109 patients, as well as to characterize risk factors for poor oncologic and functional outcomes. METHODS: We analyzed data from 109 consecutive patients who had definitive surgical treatment for soft tissue sarcoma of the hand performed between 1996 and 2019 by a single surgeon at a sarcoma center. Primary outcomes included functional outcome (assessed by Musculoskeletal Tumor Society scores), disease-free survival (DFS), and overall survival (OS). We compiled descriptive data and used a multivariable linear model to identify factors associated with functional outcomes. Kaplan-Meier methods were used to estimate 5- and 10-year DFS and OS. RESULTS: Patients had a median age of 36 years at presentation. Median follow-up was 6.1 years among patients alive at the end of follow-up. The median Musculoskeletal Tumor Society score was 29; functional outcome was worse among patients with high-grade tumors or complications. Among the 107 patients who became disease-free, there were four local recurrences (one with metastasis), six distant recurrences, and one death without recurrence. All local recurrences were deep tumors (two myxofibrosarcoma and two myxoinflammatory fibrosarcoma). Estimated 5- and 10-year DFS rates were 89% (95% confidence interval [CI]: 83% to 96%) and 88% (95% CI: 80% to 95%). There were seven deaths, and the estimated 5- and 10-year OS rates were 95% (95% CI: 90% to 100%) and 92% (95% CI: 84% to 100%). Larger tumor size and higher stage at diagnosis were associated with shorter DFS and OS in univariable analyses; low event rates precluded multivariable analysis of survival. CONCLUSIONS: Aggressive disease-specific surgical and multidisciplinary treatment can yield long DFS and OS, and good functional outcomes. However, complications and high-grade tumors are associated with worse functional scores. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

The Role of Denosumab in the Treatment of Primary Tumors of Bone.

Many hand surgeons treat benign bone tumors without referral to orthopedic oncologists. However, there have been considerable advances in medical therapy for some of these tumors, with which hand surgeons may not be as familiar. This review focuses on the mechanism and uses of denosumab in the treatment of benign tumors of bone. Although the hand surgeon may not be directly prescribing this therapy, they are often the only physician treating the patient for these conditions. As such, awareness regarding the use of this therapy in reducing pain, decreasing tumor volume, and treatment of potential lung metastases is critical to those taking on these cases without the support of an orthopedic oncologist. This article aims to familiarize hand surgeons with denosumab to help promote knowledge of this therapeutic option and the potential role of this medication in the treatment of primary bone tumors in the hand.

Impact of Patient and Tumor Characteristics on Range of Motion and Recurrence Following Treatment of Enchondromas of the Hand.

PURPOSE: The approach to the treatment of enchondromas of the hand is varied, and there is no clear consensus on graft source, fixation, or need for intraoperative adjuvant therapy. We reviewed a cohort of patients who underwent curettage and bone grafting with cancellous allograft chips without internal fixation or adjuvant therapy and reported on postoperative range of motion (ROM) and recurrence rates. METHODS: We performed a retrospective review of patients who underwent surgical treatment for hand enchondroma over a 23-year period. We collected information on demographics and presenting enchondroma characteristics, including Takigawa classification and presence of pathologic fracture or associated syndromes. Patients were treated with open biopsy with curettage and grafting with cancellous allograft chips. Postoperative ROM, complications, and recurrences were recorded. RESULTS: Our series included 111 enchondromas in 104 patients. Seventeen of 104 patients (16%) had a diagnosis of Ollier disease. Average length of follow-up was 3.1 years. Eighty-one percent of patients achieved full ROM. Treatment of patients who presented with preoperative pathologic fracture resulted in a greater frequency of reduced postoperative ROM at 28% (9/32) compared to 15% (11/72) of those patients who did not present with preoperative pathologic fracture. Local recurrence developed in 5 of 50 (10%) patients with a minimum of 2 years of follow-up. Local recurrence occurred at higher-than-average rates in patients with giant form Takigawa classification (43%, 3/7) and Ollier disease (23%, 3/13). CONCLUSIONS: Treatment of enchondromas with biopsy, curettage, and allograft results in full ROM in 81% of patients. Patients with preoperative pathologic fracture should be advised of a greater risk of postoperative extension deficit. Recurrence remains rare and is associated with syndromic presentation and giant form lesions. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Pigmented Nail Lesions: When to Observe, When to Biopsy, When to Widely Excise, and When to Amputate?

Pigmented nail lesions are challenging problems. The differential diagnosis is broad and ranges from common self-limiting conditions, such as subungual hematoma and infection, to potentially fatal conditions, such as subungual melanoma. Clinical assessment and adjuncts, such as dermoscopy and imaging, are usually insufficient to establish a diagnosis, and a nail bed biopsy is often required. However, this is not an innocuous procedure and may result in permanent nail deformity. In addition, subjecting every patient with nail pigmentation to a biopsy will result in an unacceptably high rate of negative test results. Furthermore, histopathologic diagnosis of subungual melanoma remains challenging for several reasons. Once the diagnosis of subungual melanoma is established, the definitive treatment is controversial because the existing guidelines have largely been adapted from those for cutaneous melanoma. This review presents an approach to the diagnosis and management of pigmented subungual lesions and subungual melanoma, in particular, on the basis of the latest available evidence.

The critical difference in the DASH (Disabilities of the Arm, Shoulder, and Hand) outcome measure after essential upper extremity tumor surgery.

BACKGROUND: The DASH (Disabilities of the Arm, Shoulder, and Hand) is a scored questionnaire that is widely used to evaluate the health-related quality of life of patients with upper limb musculoskeletal disorders. However, numerical changes in the measure scores lack clinical significance without meaningful threshold change values of outcome measures that are diagnostically specific. The minimal clinically important difference (MCID) is useful for the interpretation of scores by defining the smallest change that a patient would perceive. However, the MCIDs of the scores in orthopedic oncology patients has not been reported. We aimed to determine the MCIDs of the measure in orthopedic oncology patients. METHODS: Data from our health-related quality of life database from 1999 to 2005 were retrospectively reviewed after institutional review board approval. Seventy-eight patients who underwent surgery and completed 2 surveys during postoperative follow-up were evaluated. Two different methods were used to estimate the MCIDs: distribution-based and anchor-based approaches (the latter used receiver operating characteristic analysis). RESULTS: Using distribution-based methods, the MCIDs of the DASH questionnaire were 7.4 and 8.3 by half standard deviation and the 90% interval of minimal detectable change, respectively. By anchor-based method (receiver operating characteristic analysis), the MCID was 8.3. CONCLUSION: The MCID values calculated by each method validates that the results for upper extremity oncology patients were similar to those reported in other orthopedic conditions. These results identify the threshold for meaningful improvements in DASH scores in orthopedic oncology patients and establish the reference to evaluate health-related quality of life and the outcomes of upper extremity oncology surgery. These data should be further refined for disease- and reconstruction-specific analyses.

Myositis ossificans-like soft tissue aneurysmal bone cyst: a clinical, radiological, and pathological study of seven cases with COL1A1-USP6 fusion and a novel ANGPTL2-USP6 fusion.

Herein we described the clinical, radiological, histological, and molecular characteristics of seven soft tissue aneurysmal bone cysts (STABCs) diagnosed and managed at a tertiary cancer center and to elucidate their relationship with myositis ossificans (MO). All cases had established imaging and histopathological diagnosis of STABC and were subject to fluorescence in situ hybridization (FISH) for USP6 rearrangement and Archer® FusionPlex® targeted RNA sequencing (RNASeq) analysis to identify the fusion partner. A thorough literature review of STABC and MO was conducted. The patients presented with painful masses unpreceded by trauma, occurring most commonly in the deep soft tissue of the thigh/gluteus (4/7), and also in the supraclavicular region, the axilla, and the hand. On imaging, the lesions were frequently associated with peripheral calcification on conventional radiographs and CT (6/7), cystic components on ultrasound, as well as perilesional edema (7/7) and fluid levels (3/7) on MRI. Bone scan (1/1) showed intense radiotracer uptake. Histologically, 6/7 cases demonstrated zonal arrangements reminiscent of MO. USP6 rearrangement was found in all seven cases by FISH and/or RNASeq. RNASeq further detected COL1A1-USP6 fusion in six cases and a novel ANGPTL2-USP6 fusion in one case. Four patients underwent resection of the tumors and were disease free at their last follow-up. Three patients who underwent incisional or needle biopsies had no evidence of disease progression on imaging studies. In conclusion, the clinical, radiological, and pathological overlap between STABC and MO suggests that they are closely related entities. A novel fusion ANGPTL2-USP6 is associated with distinct clinical and pathological presentation.

Sentinel lymph node biopsy predicts systemic recurrence in digital papillary adenocarcinoma.

BACKGROUND AND OBJECTIVES: Digital papillary adenocarcinoma (DPA) is a rare, aggressive neoplasm of sweat gland origin. It can recur at local, regional, or distant sites. There is limited knowledge about the role of sentinel lymph node biopsy (SLNB) in predicting recurrence in these patients. We present our experience with this uncommon tumor to evaluate the role of SLNB in predicting outcome. METHODS: Medical records of all patients who underwent surgical treatment for biopsy-proven upper extremity DPA at the study institution were reviewed. Descriptive statistics and Fisher's exact test were used to analyze data. RESULTS: Twenty-one patients were identified. Most patients were male (71%), and the median age was 51 years. SLNB was performed in 18 patients; three were positive for nodal metastatic disease (17%). At a median follow-up of 53 months, there were no local recurrences and two cases of systemic recurrence. No patient with a negative sentinel lymph node has evidence of metastasis or recurrence. Fisher's exact test demonstrated a significant association between a positive SLNB and recurrence (P = .02). CONCLUSION: SLNB revealed metastatic disease in 17% of patients with DPA and appears to predict systemic recurrence in this small series.

Atypical lipomatous tumor of the hand with transformation to dedifferentiated liposarcoma: a case report.

Atypical lipomatous tumor/well-differentiated liposarcoma is the most common sarcoma of soft tissue in adults. We describe the clinical, radiologic, and pathologic features of an atypical lipomatous tumor arising within the soft tissue of the left hand of a 68-year-old female that underwent transformation to dedifferentiated liposarcoma and eventually metastasized. At initial presentation, imaging demonstrated an extensively calcified fatty soft tissue mass with displacement of the digits. Following biopsy and staged debulking, the patient subsequently developed local recurrence, dedifferentiation, and widespread metastases to the lungs, pancreas, bone, and soft tissues. To our knowledge, this is the first case of a cytogenetically proven atypical lipomatous tumor of the hand that has undergone dedifferentiation with widespread metastases.

Recurrent BRAF Gene Rearrangements in Myxoinflammatory Fibroblastic Sarcomas, but Not Hemosiderotic Fibrolipomatous Tumors.

Myxoinflammatory fibroblastic sarcoma (MIFS) is a low grade soft tissue sarcoma with a predilection for acral sites, being associated with a high rate of local recurrence but very infrequent distant metastases. Although a t(1;10) translocation resulting in TGFBR3-MGEA5 fusion has been reported as a recurrent genetic event in MIFS, this abnormality is seen only in a subset of cases. As no studies to date have investigated the spectrum of alternative genetic alterations in TGFBR3-MGEA5 fusion negative MIFS, we undertook a genetic analysis of this particular cohort for further molecular classification. Triggered by an index case occurring in the finger of a 37-year-old female and harboring a novel TOM1L2-BRAF fusion by targeted RNA sequencing we investigated potential recurrent BRAF abnormalities by screening a large group of 19 TGFBR3-MGEA5 fusion negative MIFS by fluorescence in situ hybridization. There were 6 (32%) additional MIFS with BRAF genetic abnormalities, including 5 gene rearrangements and one showing BRAF amplification. Interestingly, VGLL3 amplification, a recurrent genetic abnormality coexisting with t(1;10) in some MIFS, was also detected by fluorescence in situ hybridization in 4/6 (67%) BRAF-rearranged MIFS, but not in the BRAF-amplified case. Up-regulated VGLL3 mRNA expression was also demonstrated in the index case by RNA sequencing. The 7 BRAF-rearranged/amplified MIFS arose in the fingers (n=3), and 1 each in wrist, forearm, foot, and knee, of adult patients (36 to 74 y; M:F=4:3). The histologic spectrum ranged from predominantly solid growth of plump histiocytoid to epithelioid tumor cells with focal myxoid change to a predominantly myxoid background with scattered tumor cells. Varying degree of inflammatory infiltrates and large tumor cells with virocyte-like macronucleoli were observed in most cases. Immunohistochemical stains of phosphorylated ERK, a downstream effector of BRAF activation, were positive in all 4 cases tested (2 diffuse strong, 2 focal strong). Unlike t(1;10), BRAF rearrangements were only found in MIFS but not in 6 hemosiderotic fibrolipomatous tumor (HFLT) lacking TGFBR3-MGEA5 fusions (including 2 pure HFLT, 2 hybrid HFLT-MIFS, and 2 associated with pleomorphic hyalinizing angiectatic tumors).

Pathologically Benign Lymph Nodes Can Mimic Malignancy on Imaging in Patients With Angiomatoid Fibrous Histiocytoma.

BACKGROUND: Angiomatoid fibrous histiocytoma (AFH) is a rare soft tissue neoplasm, and its rarity makes studying it difficult. We found that several of our patients with AFH presented with radiologically suspicious local lymph nodes that were sampled because of their imaging characteristics, but the nodes proved to be benign on pathologic evaluation. Although the frequency of this finding is unknown, it seems important for orthopaedic oncologists who care for patients with AFH to know whether suspicious-appearing associated nodes in these patients warrant aggressive management. QUESTIONS/PURPOSES: (1) How often do patients with newly diagnosed AFH present with radiologically suspicious lymph nodes? (2) How often are the radiologically suspicious nodes malignant on pathologic evaluation? METHODS: In this retrospective, Health Insurance Portability and Accountability Act-compliant study, we used a hospital database to identify all 54 patients treated at our hospital for AFH between 1993 and 2016. This study was performed with institutional review board waiver. All of the patients were considered potentially eligible for analysis. Of the patients, 19 (35%) had pretherapy imaging; during the period in question, pretherapy imaging generally was obtained when there was uncertainty regarding extent of disease. All patients who had imaging underwent MRI, and four also had fluorodeoxyglucose positron emission tomography (FDG PET/CT). Imaging reports were reviewed to identify which patients had nodes that were called suspicious in the reports. All patients with nodes described as suspicious on imaging underwent subsequent pathologic analysis for the presence or absence of metastatic AFH cells in the node. RESULTS: Seven of 19 patients with pretherapy imaging had local lymph nodes called suspicious for nodal metastases. Pathologic analysis of these nodes showed they were malignant in only one patient, whereas six patients had nodes that were histologically benign despite suspicious imaging findings. Benign nodes measured as much as 3.2 × 1.8 cm on MRI and showed maximum standardized uptake values up to 10.9 on FDG PET/CT. CONCLUSIONS: Patients with newly diagnosed AFH present with benign lymph nodes that are mistaken for malignancy on imaging. Orthopaedic surgeons and radiologists should be aware of this finding in patients with AFH. Less-invasive management of suspicious nodes, such as image-guided biopsy, may be preferable to nodal resections, as this will help decrease the aggressiveness of surgery for patients with newly diagnosed AFH. LEVEL OF EVIDENCE: Level IV, diagnostic study.

Giant Cell Tumor of Distal Radius After Open Reduction Internal Fixation for Distal Radius Fracture.

CASE: A 77-year-old woman presented with volar wrist pain 1.5 years after undergoing distal radius volar locked plating for fracture. Radiographs and CT were notable only for plate prominence, and she was admitted for removal of hardware. Intraoperatively, a large cavitary bone lesion was found. Histopathology demonstrated a giant cell tumor of the bone. Definitive management consisted of wide en bloc resection and osteoarticular allograft reconstruction, which achieved local control and an acceptable clinical result. CONCLUSION: Although not previously described, a giant cell tumor of the bone may develop after fracture. Metal artifact in an area of previous internal fixation can make recognition challenging, but dual-energy CT can be used to decrease this artifact. Local control can be achieved with wide excision and reconstruction.

Extremity amputations: principles, techniques, and recent advances.

It is estimated that approximately 1.7 million Americans are living with the loss of a limb, and this number is expected to nearly double by 2050. The most common reasons for amputation include vascular compromise, trauma, cancer, and congenital deformities. Orthopaedic surgeons are often called on to manage patients requiring an amputation or those with amputation-related conditions. It is helpful to review the principles and techniques for performing lower and upper limb amputations, with a focus on common complications and how to avoid them and to be familiar with recent advances in prosthetic design and management of a residual limb.

Characteristics of glomus tumors in the hand not diagnosed on magnetic resonance imaging.

PURPOSE: To determine whether the diagnosis of hand glomus tumors by magnetic resonance imaging (MRI) is associated with tumor size, tumor pathology, tumor location, and/or clinical suspicion. METHODS: We reviewed our pathology database for patients with hand glomus tumors diagnosed between 2006 and 2013 and included those patients who had preoperative MRI at our institution. We excluded patients with recurrent and persistent tumors. Magnetic resonance imaging reports were reviewed for clinical history, tumor location, and associated bone erosion. Pathology reports were reviewed for diagnosis and tumor size. We classified MRI studies as positive (glomus tumor diagnosis), negative (no mention of glomus tumor as possible diagnosis), or indeterminate (glomus tumor mentioned as possible differential diagnosis). Fisher exact test was used to compare positive studies and those that were nondiagnostic (ie, either negative or indeterminate). RESULTS: Of the 46 patients who had pathologically confirmed hand glomus tumors, 38 had preoperative MRI studies. A total of 24 MRI studies were positive, 5 were indeterminate, and 7 were negative. Five patients had atypical pathology, 1 had a multifocal tumor, and 2 had extra-digital hand glomus tumors. Failure to diagnose glomus tumors on MRI was associated with atypical pathology, atypical location (ie, not located in the subungual region), absence of bone erosion, and lack of clinical suspicion. Tumor size was not associated with MRI diagnosis. CONCLUSIONS: In this series of 36 hand glomus tumors, one-third of MRI studies were nondiagnostic. Occurrence of nondiagnostic MRIs was more likely when glomus tumors were pathologically and/or anatomically atypical, without bone erosion, and with no or unrelated clinical history provided. These findings highlight the continued importance of clinical suspicion in glomus tumor diagnosis. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.

Proximal migration of hardware in patients undergoing midcarpal fusion with headless compression screws.

Background Scaphoid excision and limited intercarpal fusion is a common surgical procedure performed for degenerative disorders of the wrist including scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrist deformities. Postoperative screw migration is a rare but devastating complication that can result in severe degenerative changes in the radiocarpal joint. Questions/Purposes The purpose of this study is to report on a series of patients who developed proximal migration of their hardware following limited intercarpal fusions with headless compression screws. Patients and Methods Four patients were identified between 2001 and 2012 who were indicated for and underwent scaphoid excision and midcarpal fusions with headless compression screw fixation and subsequently developed hardware migration with screw protrusion into the radiocarpal joint. Detailed chart review was performed. Results Mean age at surgery was 64 years (57-69 years). All patients had the diagnosis of SLAC wrist. Mean time to detection of failure was 6 months (4-8 months). All patients demonstrated radiographic union prior to failure based on plain films. Radiographs revealed screw backout with erosion of the radial lunate facet in all patients. Calculated carpal height ratios demonstrated a drop from an average 44.2% to 39.5% at the time of hardware migration. All four patients underwent hardware removal. One patient was not indicated for any further surgery, and two patients underwent further revision surgery. All three patients reported complete pain relief. One patient refused a salvage procedure and had subsequent persistent pain. Conclusions This study reports a serious complication of scaphoid excision and midcarpal fusion performed with headless compression screws. We advise surgeons to be aware of this potential complication and consider employing methods to reduce the risk of hardware migration. Additionally, we recommend at least 8 months of clinical and radiographic follow-up postoperatively to enable early intervention if necessary. Level of Evidence Level IV, therapeutic study.

USP6 gene rearrangements occur preferentially in giant cell reparative granulomas of the hands and feet but not in gnathic location.

Giant cell reparative granulomas (GCRGs) are lytic lesions that occur predominantly in the gnathic bones and occasionally in the small bones of the hands and feet. They are morphologically indistinguishable from, and are regarded as synonymous with, solid variant of aneurysmal bone cysts (ABC) in extragnathic sites. Identification of USP6 gene rearrangements in primary ABC has made possible investigating potential pathogenetic relationships with other morphologic mimics. USP6 gene alterations in giant cell-rich lesions (GCRG/ABC) of small bones of the hands and feet have not been previously studied. We investigated USP6 gene alterations in a group of 9 giant cell-rich lesions of the hands and feet and compared the findings with morphologically similar lesions including 8 gnathic GCRGs, 22 primary ABCs, 8 giant cell tumors of bone, and 2 brown tumors of hyperparathyroidism. Overall, there were 49 samples from 48 patients including 26 females and 22 males. Of the 9 lesions of the hands and feet, 8 (89%) showed USP6 gene rearrangements, whereas no abnormalities were identified in the 8 gnathic GCRGs, 2 brown tumors, or 8 giant cell tumors of bone. Of the 22 primary ABCs, 13 (59%) showed USP6 gene rearrangements. In conclusion, most GCRGs of the hands and feet represent true ABCs and should be classified as such. The terminology of GCRG should be limited to lesions from gnathic location. Fluorescence in situ hybridization for USP6 break-apart is a useful ancillary tool in the diagnosis of primary ABCs and distinguishing them from GCRGs and other morphologically similar lesions.

Attrition or rupture of digital extensor tendons due to carpal boss: report of 2 cases.

We present 2 cases that demonstrate the potential for tendon involvement in the presence of a carpal boss. In the first, a patient presented with tendon rupture without antecedent pain. In the second, pain and tendon irritation prompted magnetic resonance imaging that revealed tendon fraying, which was confirmed at surgery. These cases illustrate the potential for tendinous sequelae of a carpal boss. Advanced imaging may be considered when tendon irritation is clinically suspected. Attention to the possibility of tendon rupture in the setting of an otherwise asymptomatic carpal boss is advised.

Immediate bone grafting and plating of the radial osteocutaneous free flap donor site.

BACKGROUND: The primary shortcoming of the osteocutaneous radial forearm flap (ORFF) in head and neck reconstruction is the high incidence of fracture at the donor site. Although several prophylactic measures are reported, combined plating with iliac crest bone graft (ICBG) of the donor site has not been previously described. Outcomes and rationale for this method of radius reconstruction are described. METHODS: Retrospective review of a prospectively maintained database identified 23 consecutive patients who underwent head and neck reconstruction using an ORFF. Flap features, method of donor-site reconstruction, and complications were evaluated. RESULTS: The initial 7 patients from the series had no intervention at the radius donor site. The next 7 patients had ICBG only, whereas the final 9 patients had both plating and ICBG placed at the donor site. The mean cross-sectional diameter and length of radius bone harvested was 30% by 7 cm, 33% by 8 cm, and 53% by 9 cm for the 3 groups, respectively. Fracture rates for the 3 groups were 29%, 14%, and 0%. There were no iliac crest donor-site complications. CONCLUSIONS: Plating combined with ICBG is a safe and effective method for radius donor-site reconstruction. This technique maximizes both early and late strength of the radius while allowing for harvest of greater segments of bone. Decreased donor-site morbidity combined with more bone available for use in oromandibular reconstruction may tip the risk-benefit scale in favor of more widespread ORFF use.

Comparison between Constrained and Semiconstrained Knee Allograft-Prosthesis Composite Reconstructions.

Allograft-prosthesis composite (APC) can restore capsular and ligamentous tissues of the knee sacrificed in a tumor extirpation. We asked if performing APC would restore knee stability and allow the use of nonconstrained arthroplasty while preventing aseptic loosening. We retrospectively compared 50 knee APCs performed with non-constrained revision knee prosthesis (Group 1) with 36 matched APCs performed with a constrained prosthesis (Group 2). In Group 1, the survival rate was 69% at five and 62% at ten years. Sixteen reconstructions were removed due to complications: eight deep infections, three fractures, two instabilities, one aseptic loosening, one local recurrence, and one nonunion. In Group 2, the survival rate was 80% at five and 53% at ten years. Nine reconstructions were removed: 3 due to deep infections, 3 to fractures, and 3 to aseptic loosening. In both groups, we observed more allograft fractures when the prosthetic stem does not bypass the host-donor osteotomy (P > 0.05). Both groups had mainly good or excellent MSTS functional results. Survival rate and functional scores and aseptic loosening were similar in both groups. A rotating-hinge APC is recommended when host-donor soft tissue reconstruction fails to restore knee instability. The use of a short prosthetic stem has a statistical relationship with APC fractures.

Compress knee arthroplasty has 80% 10-year survivorship and novel forms of bone failure.

BACKGROUND: Compliant, self-adjusting compression technology is a novel approach for durable prosthetic fixation of the knee. However, the long-term survival of these constructs is unknown. QUESTIONS/PURPOSES: We therefore determined the survival of the Compress prosthesis (Biomet Inc, Warsaw, IN, USA) at 5 and 10 actuarial years and identified the failure modes for this form of prosthetic fixation. METHODS: We retrospectively reviewed clinical and radiographic records for all 82 patients who underwent Compress knee arthroplasty from 1998 to 2008, as well as one patient who received the device elsewhere but was followed at our institution. Prosthesis survivorship and modes of failure were determined. Followup was for a minimum of 12 months or until implant removal (median, 43 months; range, 6-131 months); 28 patients were followed for more than 5 years. RESULTS: We found a survivorship of 85% at 5 years and 80% at 10 years. Eight patients required prosthetic revision after interface failure due to aseptic loosening alone (n = 3) or aseptic loosening with periprosthetic fracture (n = 5). Additionally, five periprosthetic bone failures occurred that did not require revision: three patients had periprosthetic bone failure without fixation compromise and two exhibited irregular prosthetic osteointegration patterns with concomitant fracture due to mechanical insufficiency. CONCLUSIONS: Compress prosthetic fixation after distal femoral tumor resection exhibits long-term survivorship. Implant failure was associated with patient nonadherence to the recommended weightbearing proscription or with bone necrosis and fracture. We conclude this is the most durable FDA-approved fixation method for distal femoral megaprostheses. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.