Proximal Humerus Reconstruction for Bone Sarcomas: A Critical Analysis.

¼ The proximal humerus is a common location for primary bone tumors, and the goal of surgical care is to obtain a negative margin resection and subsequent reconstruction of the proximal humerus to allow for shoulder function.¼ The current evidence supports the use of reverse total shoulder arthroplasty over hemiarthroplasty when reconstructing the proximal humerus after resection of a bone sarcoma if the axillary nerve can be preserved.¼ There is a lack of high-quality data comparing allograft prosthetic composite (APC) with endoprosthetic reconstruction of the proximal humerus.¼ Reverse APC should be performed using an allograft with donor rotator cuff to allow for soft-tissue repair of the donor and host rotator cuff, leading to improvements in shoulder motion compared with an endoprosthesis.

Reverse Shoulder Arthroplasty Megaprosthesis for Surgical Management of Severe Proximal Humeral Bone Loss.

INTRODUCTION: Shoulder arthroplasty in the setting of severe proximal humerus bone loss can be challenging. The purpose of this study was to evaluate the outcomes of a modular segmental megaprosthesis when implanted in a reverse configuration for complex primary arthroplasty, reconstruction at the time of oncologic resection, and revision shoulder arthroplasty. MATERIALS AND METHODS: A Joint Registry Database was queried to identify all shoulder arthroplasties performed at a single institution using the Comprehensive Segmental Revision System® reverse shoulder arthroplasty (SRS-RSA, Zimmer Biomet, Warsaw, IN, USA). A retrospective review of electronic medical records and radiographs was performed to record demographic data, indication, outcomes, complications, and revision surgery. RESULTS: Between February 2012 and October 2022, 76 consecutive SRS-RSA were implanted. An analysis of patients with minimum 12-month follow-up yielded 53 patients with a mean follow-up of 4.1 ± 2.43 years. Surgical complication rate in this cohort was observed in 41.5% (22/53) of cases. Overall, revision rate at final follow-up was 26.4% (14/53), with a significant difference between the primary and revision cohorts. The number of prior surgeries was a significant risk factor for revision surgery, with a hazard ratio of 1.789 (p<.001 95%CI [1.314-2.436]). When analyzing aseptic humeral loosening rates across study cohorts, a significant difference was found between the primary arthroplasty (0%, n = 0) and the revision arthroplasty cohorts (22.2%, n = 6) (p = 0.04). DISCUSSION: Reverse shoulder arthroplasty using a modular segmental megaprosthesis remains a reasonable salvage option for shoulder reconstruction in the setting of proximal humeral bone loss. Due to the substantial bone loss and soft tissue deficiencies typically present in these cases, surgeons should educate patients on the relatively high complication rate, particularly when used in the setting of a previous failed arthroplasty.

Active surveillance of diffuse-type tenosynovial giant cell tumors: A retrospective, multicenter cohort study.

BACKGROUND: Diffuse-type tenosynovial giant cell tumor (D-TGCT) is a mono-articular, soft-tissue tumor. Although it can behave locally aggressively, D-TGCT is a non-malignant disease. This is the first study describing the natural course of D-TGCT and evaluating active surveillance as possible treatment strategy. METHODS: This retrospective, multicenter study included therapy naïve patients with D-TGCT from eight sarcoma centers worldwide between 2000 and 2019. Patients initially managed by active surveillance following their first consultation were eligible. Data regarding the radiological and clinical course and subsequent treatments were collected. RESULTS: Sixty-one patients with primary D-TGCT were initially managed by active surveillance. Fifty-nine patients had an MRI performed around first consultation: D-TGCT was located intra-articular in most patients (n = 56; 95 %) and extra-articular in 14 cases (24 %). At baseline, osteoarthritis was observed in 13 patients (22 %) on MRI. Most of the patients' reported symptoms: pain (n = 43; 70 %), swelling (n = 33; 54 %). Eight patients (13 %) were asymptomatic. Follow-up data were available for 58 patients; the median follow-up was 28 months. Twenty-one patients (36 %) had radiological progression after 21 months (median). Eight of 45 patients (18 %) without osteoarthritis at baseline developed osteoarthritis during follow-up. Thirty-seven patients (64 %) did not clinically deteriorate during follow-up. Finally, eighteen patients (31 %) required a subsequent treatment. CONCLUSION: Active surveillance can be considered adequate for selected therapy naïve D-TGCT patients. Although follow-up data was limited, almost two-thirds of the patients remained progression-free, and 69 % did not need treatment during the follow-up period. However, one-fifth of patients developed secondary osteoarthritis. Prospective studies on active surveillance are warranted.

Midterm outcomes of total hip arthroplasty after internal hemipelvectomy and iliofemoral arthrodesis.

BACKGROUND AND OBJECTIVES: Recent studies have reported acceptable outcomes after arthrodesis takedown and conversion to total hip arthroplasty (THA); however, there are no reports on outcomes after oncologic resection, which are inherently complex and may portend poorer outcomes. The purpose of this study was to examine the surgical and functional outcomes of patients who underwent prior hemipelvectomy for tumor resection and were later converted to THA. METHODS: All patients who had prior iliofemoral arthrodesis after oncologic resection that were later converted to THA at a single institution were examined. Charts were reviewed for demographic information, operative information, functional outcomes, and complications/reoperations. RESULTS: All three patients in this study were males who underwent internal hemipelvectomies for chondrosarcoma. Patients were converted to THA at a mean of 26 years after arthrodesis. Mean follow-up after conversion to THA was 7.4 years. During this follow-up period, two of the three patients required revision surgery. At last follow-up, the mean Harris Hip Score was 81 and the mean Mayo Hip Score was 67, and all patients were ambulatory without significant pain. CONCLUSIONS: Overall, patients who undergo iliofemoral arthrodesis after oncologic hemipelvectomy and are later converted to THA can expect to have a reasonable outcome, despite a high rate of complications and revision surgery.

Long-term outcome of total hip arthroplasty in patients with multiple hereditary exostosis.

BACKGROUND: Multiple hereditary exostosis (MHE) is a rare autosomal dominant disorder characterized by multiple osteochondromas. There is a paucity of literature concerning total hip arthroplasty (THA) in patients with MHE. The aim of this study is to report long-term outcomes of THA in patients with MHE. METHODS: Fourteen patients undergoing 15 THA's for the treatment of osteoarthritis in the presence of osteochondromas and proximal femoral deformity secondary to MHE were reviewed. Mean age at the time of surgery and follow-up was 56 and 12 years. Seven (47%) had uncemented femoral components. Eleven hips had coxa valga on preoperative imaging. Clinical outcomes were assessed with both Harris hip scores (HHS) and Musculoskeletal Tumor Society Scores (MSTS). RESULTS: Following surgery, there was an improvement in the HHS (48-82, p < 0.01) and MSTS scores (41-70%, p < 0.01). Complications occurred in 5 patients leading to reoperation in 3 patients, of which 2 patients underwent a revision procedure at 19 and 20-years postoperative. The 10-year revision free survival was 100%. CONCLUSIONS: THA in the setting of MHE reliably improves patient function. One in three patients will have a postoperative complication; however, the long-term incidence of revision is low.

Sacral insufficiency fractures are a frequent and painful consequence of pubic symphysis osteomyelitis.

BACKGROUND: Pubic symphysis osteomyelitis can result from urosymphyseal fistula formation. High rates of sacropelvic insufficiency fractures have been reported in this population. The aim of this study was to describe the presentation and risk factors for sacral insufficiency fractures (SIF) associated with surgical treatment of pubic symphysis osteomyelitis. METHODS: A retrospective review was performed for 54 patients who underwent surgery for pubic symphysis osteomyelitis associated with a urosymphyseal fistula at a single institution from 2009 to 2022. Average age was 71 years and 53 patients (98%) were male. All patients underwent debridement or partial resection of the pubic symphysis at the time of fistula treatment. Average width of the symphyseal defect was 65 mm (range 9-122) after treatment. RESULTS: Twenty patients (37%) developed SIF at a mean time of 4 months from osteomyelitis diagnosis. Rate of sacral fracture on Kaplan-Meier analysis was 31% at 6 months, 39% at 12 months, and 41% at 2 years. Eleven patients developed SIF prior to pubic debridement and 12 patients developed new or worsening of pre-existing SIF following surgery. Width of pubic resection was higher in patients who developed SIF (76 mm vs. 62 mm), but this did not meet statistical significance (p = 0.18). CONCLUSION: Sacral insufficiency fracture is a common sequela of pubic symphysis osteomyelitis. These fractures are often multifocal within the pelvis and can occur even prior to pubic resection. Pubectomy further predisposes these patients to fracture. Clinicians should maintain a high index of suspicion for these injuries in patients with symphyseal osteomyelitis.

Whole Blood Metal Levels in the Setting of an Oncologic Endoprosthesis: Is There Cause for Concern?

BACKGROUND: Massive modular endoprostheses have become a primary means of reconstruction after oncologic resection of a lower extremity tumor. These implants are commonly made with cobalt-chromium alloys that can undergo wear and corrosion, releasing cobalt and chromium ions into the surrounding tissue and blood. However, there are few studies about the blood metal levels in these patients. QUESTION/PURPOSE: What is the whole blood cobalt and chromium ion level in patients with massive modular endoprostheses? METHODS: We performed a cross-sectional study of our total joints registry to identify patients with a history of an endoprosthetic reconstruction performed at our institution. Patients who were alive at the time of our review in addition to those undergoing an endoprosthetic reconstruction after an oncologic resection were included. Whole blood samples were obtained from 27 (14 male and 13 female) patients with a history of a lower extremity oncologic endoprosthesis. The median time from surgery to blood collection was 8 years (range 6 months to 32 years). Blood samples were collected and stored in metal-free ethylenediaminetetraacetic acid tubes. Samples were analyzed on an inductively coupled plasma mass spectrometer in an International Organization for Standardization seven-class clean room using polytetrafluoroethylene-coated instruments to reduce the risk of metal contamination. The analytical measuring range was 1 to 200 ng/mL for chromium and cobalt. Cobalt and chromium levels were considered elevated when the blood level was ≥ 1 ppb. RESULTS: Cobalt levels were elevated in 59% (16 of 27) of patients, and chromium levels were elevated in 26% (seven of 27). In patients with elevated metal ion values, 15 of 17 patients had a reconstruction using a Stryker/Howmedica Global Modular Replacement System implant. CONCLUSION: Blood metal levels were elevated in patients who received reconstructions using modular oncology endoprostheses Future work is needed to establish appropriate follow-up routines and determine whether and when systemic complications occur because of elevated metal levels and how to potentially address these elevated levels when complications occur. Prospective and retrospective collaboration between multiple centers and specialty societies will be necessary to address these unknown questions in this potentially vulnerable patient group. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Durability of intercalary endoprosthesis for humeral reconstruction.

INTRODUCTION: The humerus is a common site of metastases and primary tumors. For some patients with a segmental defect and/or diaphyseal cortical destruction a cemented intercalary device may provide a more reliable construct, however data on their use is limited. METHODS: We reviewed 43 (28 male and 15 female) patients treated with an intercalary humeral spacer at a single tertiary referral center between 1989 and 2022. Humeral lesions were most commonly secondary to metastatic disease (n = 29, 68%), with 25 (58%) patients presenting with a pathologic fracture. Mean age and body mass index were 66 years and 27.9 kg/m2 . First generation taper joint device were used in 22 patients and second-generation lap device in 21 patients. RESULTS: Following reconstruction the 2-year overall survival was 30%. Mechanical complications occurred in 11 patients, most commonly aseptic loosening (n = 6, 14%). With death as a competing risk, the cumulative incidence of mechanical failure was 28% at 2-years postoperative. Following the procedure, mean Musculoskeletal Tumor Society scores was 70% and mean shoulder elevation was 87°. CONCLUSION: Reconstruction of the humeral diaphysis with an intercalary endoprosthesis provides restoration of function of the upper extremity, however, is associated with one in four patients having mechanical failure.

Advances in Oncologic Shoulder Girdle Resection and Reconstruction.

The bony shoulder girdle consists of the clavicle, humerus, and scapula, which work synergistically to form a complex articulation that is essential for use of the upper extremity. The shoulder girdle is the most common location for primary and secondary bone tumors in the upper extremity, and following resection of these tumors, reconstruction of the upper extremity is challenging. Compared with those in the lower extremity, reconstructive techniques in the upper extremity have historically been unreliable and fraught with complications and poor functional outcomes. Newer reconstructive techniques using reverse total shoulder arthroplasty and functional muscle flaps have shown promise to improve outcomes while reducing complications for proximal humerus reconstructions. Despite these advancements, reconstruction following scapulectomy remains challenging and is still associated with more frequent complications and compromised function.

Controversies in Oncologic Pediatric Limb Salvage.

With advances in chemotherapy and radiation therapy, surgical treatment of patients with bone sarcomas has advanced from most patients undergoing an amputation to now most patients undergoing a limb salvage procedure. With the advances of limb salvage surgical techniques, reconstructive procedures have expanded to include autografts, allografts, endoprosthetic replacements, and rotationplasty. In a growing child, the decision to perform each of these reconstructive options is individualized and each needs to be considered to provide the patient with the optimal oncologic and functional outcome, while being durable to minimize the risk of complications and subsequent surgeries.

Reconstruction following oncological iliosacral resection.

Aims: The sacroiliac joint (SIJ) is the only mechanical connection between the axial skeleton and lower limbs. Following iliosacral resection, there is debate on whether reconstruction of the joint is necessary. There is a paucity of data comparing the outcomes of patients undergoing reconstruction and those who are not formally reconstructed. Methods: A total of 60 patients (25 females, 35 males; mean age 39 years (SD 18)) undergoing iliosacral resection were reviewed. Most resections were performed for primary malignant tumours (n = 54; 90%). The mean follow-up for surviving patients was nine years (2 to 19). Results: Overall, 27 patients (45%) were reconstructed, while 33 (55%) had no formal reconstruction. There was no difference in the use of chemotherapy (p = 1.000) or radiotherapy (p = 0.292) between the groups. Patients with no reconstruction had a mean larger tumour (11 cm (SD 5) vs 8 cm (SD 4); p = 0.014), mean shorter operating times (664 mins (SD 195) vs 1,324 mins (SD 381); p = 0.012), and required fewer blood units (8 (SD 7) vs 14 (SD 11); p = 0.012). Patients undergoing a reconstruction were more likely to have a deep infection (48% vs 12%; p = 0.003). Nine reconstructed patients had a hardware failure, with five requiring revision. Postoperatively 55 (92%) patients were ambulatory, with no difference in the proportion of ambulatory patients (89% vs 94%; p = 0.649) or mean Musculoskeletal Tumor Society Score (59% vs 65%; p = 0.349) score between patients who did or did not have a reconstruction. The ten-year disease-specific survival was 69%, with no difference between patients who were reconstructed and those who were not (78% vs 45%; p = 0.316). There was no difference in the rate of metastasis between the two groups (hazard ratio (HR) 2.78; p = 0.102). Conclusion: Our results demonstrate that SIJ reconstruction is associated with longer operating times, greater need for blood transfusion, and more postoperative infections, without any improvement in functional outcomes when compared to patients who did not have formal SIJ reconstruction.

Oncological and functional outcomes after resection of malignant tumours of the scapula.

Aims: The scapula is a rare site for a primary bone tumour. Only a small number of series have studied patient outcomes after treatment. Previous studies have shown a high rate of recurrence, with functional outcomes determined by the preservation of the glenohumeral joint and deltoid. The purpose of the current study was to report the outcome of patients who had undergone tumour resection that included the scapula. Methods: We reviewed 61 patients (37 male, 24 female; mean age 42 years (SD 19)) who had undergone resection of the scapula. The most common resection was type 2 (n = 34) according to the Tikhoff-Linberg classification, or type S1A (n = 35) on the Enneking classification. Results: The ten-year disease-specific survival was 76%. High tumour grade (hazard ratio (HR) 4.27; p = 0.016) and a total resection of the scapula (HR 3.84; p = 0.015) were associated with worse survival. The ten-year metastasis-free and local recurrence-free survivals were 82% and 86%, respectively. Total scapular resection (HR 6.29; p = 0.004) was associated with metastatic disease and positive margins were associated with local recurrence (HR 12.86; p = 0.001). At final follow-up, the mean shoulder forward elevation and external rotation were 79° (SD 62°) and 27° (SD 25°), respectively. The most recent functional outcomes evaluated included the mean Musculoskeletal Tumor Society Score (76% (SD 17%)), the American Shoulder and Elbow Score (73% (SD 20%)), and the Simple Shoulder Test (7 (SD 3)). Preservation of the glenoid (p = 0.001) and scapular spine (p < 0.001) improved clinical outcomes; interestingly, preservation of the scapular spine without the glenoid improved outcomes (p < 0.001) compared to preservation of the glenoid alone (p = 0.05). Conclusion: Resection of the scapula is a major undertaking with an oncological outcome related to tumour grade, and a functional outcome associated with the status of the scapular spine and glenoid. Positive resection margins are associated with local recurrence.

A Ready-to-Use Purified Exosome Product for Volumetric Muscle Loss and Functional Recovery.

Large skeletal muscle defects owing to trauma or following tumor extirpation can result in substantial functional impairment. Purified exosomes are now available clinically and have been used for wound healing. The objective of this study was to evaluate the regenerative capacity of commercially available exosomes on an animal model of volumetric muscle loss (VML) and its potential translation to human muscle injury. An established VML rat model was used. In the in vitro experiment, rat myoblasts were isolated and cocultured with 5% purified exosome product (PEP) to validate uptake. Myoblast proliferation and migration was evaluated with increasing concentrations of PEP (2.5%, 5%, and 10%) in comparison with control media (F10) and myoblast growth medium (MGM). In the in vivo experiment, a lateral gastrocnemius-VML defect was made in the rat hindlimb. Animals were randomized into four experimental groups; defects were treated with surgery alone, fibrin sealant, fibrin sealant and PEP, or platelet-rich plasma (PRP). The groups were further randomized into four recovery time points (14, 28, 45, or 90 days). The isometric tetanic force (ITF), which was measured as a percentage of force compared with normal limb, was used for functional evaluation. Florescence microscopy confirmed that 5% PEP demonstrated cellular uptake ∼8-12 h. Compared with the control, myoblasts showed faster proliferation with PEP irrespective of concentration. PEP concentrations of 2.5% and 5% promoted myoblast migration faster compared with the control (<0.05). At 90 days postop, both the PEP and fibrin sealant and PRP groups showed greater ITF compared with control and fibrin sealant alone (<0.05). At 45 days postop, PEP with fibrin sealant had greater cellularity compared with control (<0.05). At 90 days postop, both PEP with fibrin sealant and the PRP-treated groups had greater cellularity compared with fibrin sealant and control (<0.05). PEP promoted myoblast proliferation and migration. When delivered to a wound with a fibrin sealant, PEP allowed for muscle regeneration producing greater functional recovery and more cellularity in vivo compared with untreated animals. PEP may promote muscle regeneration in cases of VML; further research is warranted to evaluate PEP for the treatment of clinical muscle defects.

Multidisciplinary Treatment of Merkel Cell Carcinoma of the Extremities: Outcomes and Factors Associated with Poor Survival in Nodal Disease.

Merkel cell carcinoma (MCC) has a tendency for lymphatic spread and locoregional recurrence, although there is little data examining the risk factors for patients with lymph node-positive extremity lesions. The purpose of the current study was to examine the outcomes and risk factors associated with nodal metastasis in extremity MCC. We retrospectively reviewed the medical record of 120 patients with extremity MCC evaluated at our institution between 1994 and 2021. The mean age of this cohort was 71 years; 33% of patients were female; and 98% were Caucasian. Seventy-eight (65%) patients presented with localized disease. Thirty-seven (31%) patients had stage III disease, and five (4%) patients had stage IV disease. Treatment of primary lesions consisted primarily of margin-negative excision and adjuvant radiotherapy. Nodal metastases were most treated with adjuvant radiation or completion lymph node dissection. Five-year disease-specific survival in our series was 88% for patients with localized disease, 89% for stage IIIa disease, 40% for stage IIIb disease and 42% for stage IV. Factors associated with worse survival included immunosuppression and macroscopic nodal disease. In conclusion, extremity MCC has a low rate of local recurrence when treated with margin-negative excision and adjuvant radiation. However, treatment of nodal metastases remains a challenge with high rates of recurrence and mortality, particularly for patients who are immunosuppressed or who have macroscopic nodal disease.

Targeted Muscle Reinnervation to Reduce Postoperative Pain in Patients Undergoing Hindquarter Resections.

BACKGROUND/AIM: Pre-emptive targeted muscle reinnervation (TMR) at the time of amputation results in less phantom limb pain (PLP) compared with untreated amputee controls. There is limited literature describing the technique in patients undergoing hindquarter amputation despite up to 90% of these patients reporting PLP and 50% presenting with painful neuroma. The purpose of the current study was to describe the motor nerves accessible through a primary hind-quarter amputation to be used for TMR and review pain outcomes in clinical case correlates of patients with TMR. PATIENTS AND METHODS: Six limbs were obtained from three fresh adult cadavers and proximal sensory and motor nerves were dissected. A review of patients undergoing hindquarter amputation with TMR was conducted. RESULTS: Transfers for the sciatic, femoral, and obturator nerves were identified in cadavers. In reviews of patients, they were taking narcotic and neuro-leptic pain medication for a mean of 23 days and 168 days. At most recent follow-up, no patient reported debilitating phantom pain nor pain associated with neuromas. CONCLUSION: Given the positive preliminary results in our study group as well as the accessible neuroanatomy, pre-emptive TMR should be considered at the time of surgery to limit PLP and dependence on pain medications.

Management of giant cell tumors of the distal radius.

Background: The distal radius is the most common location for giant cell tumors (GCT) in the upper extremity. Treatment should balance the goals of maximizing function and minimizing recurrence and other complications. Given the complexity in surgical treatment, various techniques have been described without clear standards of treatment. Objectives: The purpose of this review is to provide an overview of evaluation of patients presenting with GCT of the distal radius, discuss management, and provide an updated summary on outcomes of treatment options. Conclusion: Surgical treatment should consider tumor Grade, involvement of the articular surface, and patient-specific factors. Options include intralesional curettage and en bloc resection with reconstruction. Within reconstruction techniques, radiocarpal joint preserving and sparing procedures can be considered. Campanacci Grade 1 tumors can be successfully treated with joint preserving procedures, whereas for Campanacci Grade 3 tumors consideration should be given to joint resection to prevent recurrence. Treatment of Campanacci Grade 2 tumors is debated in the literature. Intralesional curettage and adjuvants can successfully treat cases where the articular surface can be preserved, while en-bloc resection should be used in cases where the articular surface cannot undergo aggressive curettage. A variety of reconstructive techniques are used for cases needing resection, with no clear gold standard. Joint sparing procedures preserve motion at the wrist joint, whereas joint sacrificing procedures preserve grip strength. Choice of reconstructive procedure should be made based on patient-specific factors, considering relative functional outcomes, complications, and recurrence rates.

Tibial intraneural ganglion cysts at the superior tibiofibular joint treated with joint resection alone: a proof of concept.

BACKGROUND: Intraneural ganglion cysts involving the tibial nerve are rare. Recent evidence has supported an articular (synovial) theory to explain the joint-related origin of these cysts; however, optimal operative treatment for cysts originating from the STFJ remains poorly understood. Therefore, we present a novel strategy: addressing the joint itself without addressing the articular branch and/or the cyst. METHODS: Records of patients with tibial intraneural ganglion cysts with a connection to the STFJ who were treated with a joint resection alone at a single academic institution were reviewed. The clinicoradiographic features, operative intervention, and postoperative course were recorded. RESULTS: We identified a consecutive series of 7 patients. These patients (4/7 male, 57%) were 43 (range 34-61) years of age and all presented with symptoms of neuropathy. The patients underwent resection of the synovial surfaces of the STFJ without disconnection of the articular branch or decompression of the cyst. Postoperatively, three patients regained partial motor function (43%, n=7), although four patients noted continued sensory abnormality (57%, 4/7). All six patients with postoperative MRIs had some evidence of regression of the cyst. CONCLUSIONS: This novel surgical technique serves as a proof of concept-highlighting the fact that treating the primary source (the joint origin) can be effective in eliminating the secondary problem (the cyst itself). While this study shows that this simplified approach can be employed in select cases, we believe that superior results (faster, fuller recovery) can be achieved with combinations of disconnecting the articular branch, decompressing the cyst, and/or resecting the joint.

The Role of 3D Printing in Treatment Planning of Spine and Sacral Tumors.

Three-dimensional (3D) printing technology has proven to have many advantages in spine and sacrum surgery. 3D printing allows the manufacturing of life-size patient-specific anatomic and pathologic models to improve preoperative understanding of patient anatomy and pathology. Additionally, virtual surgical planning using medical computer-aided design software has enabled surgeons to create patient-specific surgical plans and simulate procedures in a virtual environment. This has resulted in reduced operative times, decreased complications, and improved patient outcomes. Combined with new surgical techniques, 3D-printed custom medical devices and instruments using titanium and biocompatible resins and polyamides have allowed innovative reconstructions.

Comparison of Fixation Techniques for Lower Extremity Rotationplasty.

BACKGROUND: Rotationplasty is a reconstructive, limb-sparing surgery indicated for patients with lower extremity musculoskeletal tumors. The procedure involves rotation of the distal lower extremity to allow the ankle to function as the new knee joint and provide an optimum weight-bearing surface for prosthetic use. Historically there is limited data comparing fixation techniques. The purpose of this study is to compare clinical outcomes between intramedullary nailing (IMN) and compression plating (CP) in young patients undergoing rotationplasty. METHODS: A retrospective review of 28 patients with a mean age of 10±4 years undergoing a rotationplasty for either a femoral (n=19), tibial (n=7), or popliteal fossa (n=2) tumor was performed. The most common diagnosis was osteosarcoma (n=24). Fixation was obtained with either an IMN (n=6) or CP (n=22). Clinical outcomes of patients undergoing rotationplasty were compared between the IMN and CP groups. RESULTS: Surgical margins were negative in all patients. The mean time to union was 24 months (range 6 to 93). There was no difference in the meantime to the union between patients treated with an IMN versus those with a CP (14±16 vs. 27±26 mo, P =0.26). Patients undergoing fixation with an IMN were less likely to have a nonunion (odds ratio: 0.35, 95% confidence interval: 0.03-3.54, P =0.62). Postoperative fracture of the residual limb only occurred in patients undergoing CP fixation (n=7, 33% vs. n=0, 0%, P =0.28). Postoperative fixation complications occurred in 13 (48%) patients, most commonly a nonunion (n=9, 33%). Patients undergoing fixation with a CP were more likely to have a postoperative fixation complication (odds ratio: 20, 95% CI: 2.14-186.88, P <0.01). CONCLUSIONS: Rotationplasty is an option for limb salvage for young patients with lower extremity tumors. The results of this study reveal fewer fixation complications when an IMN can be used. As such, IMN fixation should be considered for patients undergoing a rotationplasty, though equipoise should be shown by surgeons when determining technique.

Is Bone Marrow Aspiration and Biopsy of Clinical Importance in the Initial Staging of Extraskeletal Ewing Sarcoma?

BACKGROUND: Extraskeletal Ewing sarcoma are rare tumors within the Ewing sarcoma family. Initial staging studies for extraskeletal Ewing sarcoma historically have included imaging and bone marrow aspiration and biopsy (BMAB). However, recent studies on Ewing sarcoma of bone have questioned the utility of BMAB in the initial staging of patients, but no studies of which we are aware have evaluated the role of BMAB in extraskeletal Ewing sarcoma. We suspected that BMAB was of low diagnostic yield in patients with extraskeletal Ewing sarcoma and exposed patients to potential morbidity without an impact on their clinical course. QUESTION/PURPOSE: Is BMAB a useful test in the staging of extraskeletal Ewing sarcoma? METHODS: Between January 1996 and December 2021, our institution evaluated 109 patients with a listed diagnosis of extraskeletal Ewing sarcoma. Those patients were retrospectively reviewed for this study. Of those, we considered patients with biopsy-confirmed diagnosis of extraskeletal Ewing sarcoma. Biopsy was performed based on institutional protocols, with all diagnoses assigned by a board-certified pathologist. Based on that criteria, 96% (105 of 109) were eligible. An additional 18% (20 of 109) were excluded because records of their initial diagnostic and staging workup were not available. This left 78% (85 of 109) for analysis. Of those, 52% (44 of 85) were male. The average age was 32 ± 16 years. Primary tumor locations included extremities in 26% (22 of 85), paraspinal in 20% (17 of 85), chest in 19% (16 of 85), retroperitoneum in 13% (11 of 85), intraabdominal in 12% (10 of 85), intrapelvic in 7% (6 of 85), and head or neck in 4% (3 of 85). Initial diagnostic and staging information, including the use of PET-CT, bone scan, CT chest, and BMAB, was collected. Metastatic disease at the time of presentation or during follow-up was noted. The utility of BMAB was determined by the rate of positive tests in those undergoing BMAB during the initial staging process. Descriptive statistical analysis was sufficient to address the study question, and therefore no comparative statistics were performed. RESULTS: BMAB was obtained during the initial staging process in 64% (54 of 85) of patients. This BMAB was negative in all 54 patients, including those with known metastatic disease. CONCLUSION: Diagnosing metastatic disease in extraskeletal Ewing sarcoma is important as the presence of metastases at diagnosis adversely affects prognosis. The routine use of BMAB in the staging process of extraskeletal Ewing sarcoma is of low diagnostic yield. BMAB is unlikely to diagnose metastatic involvement even in patients with known metastases to bone. We do not have enough data to suggest whether other modalities, such as PET-CT, might be more useful. Similar studies should be pursued to determine the utility of the remainder of staging modalities in patients with extraskeletal Ewing sarcoma to elucidate the most efficient and effective staging protocol. LEVEL OF EVIDENCE: Level III, diagnostic study.