Modular Endoprosthetic Reconstruction Research Articles

Advancing pediatric bone sarcoma care: navigating complications and innovating solutions in limb salvage and reconstruction-why, when, and how to treat limb length inequalities.

Pediatric bone sarcomas, particularly osteosarcomas, present unique challenges in the realm of orthopedic oncology, given their predilection for the metaphyseal regions of long bones and the intricate balance required between achieving oncologic control and preserving limb function. This abstract encapsulates findings from a comprehensive review aimed at advancing pediatric bone sarcoma care, focusing on navigating the complications and innovating solutions for complications of limb salvage and reconstruction focusing on limb length inequalities and accompanying bone defects. Advancements in imaging, surgical techniques, and adjuvant therapies have shifted the paradigm from amputation to limb-sparing surgeries, albeit with significant challenges, especially in young patients where growth potential complicates reconstructive outcomes. The series highlights the complexity of managing limb length discrepancies (LLD), the cornerstone of limb salvage challenges, and the innovative approaches to address them, including modular endoprosthetic reconstruction with expandable prostheses, magnetic lengthening nails and biological reconstruction strategies like vascularized fibula grafts. This review underlines the importance of a multidisciplinary approach in managing pediatric bone sarcomas, where the aim extends beyond mere survival to ensuring quality of life through functional limb preservation. It highlights the need for ongoing innovation in surgical and reconstructive techniques tailored to the pediatric population's unique needs, emphasizing the potential of emerging technologies and methodologies to improve outcomes. Future research should aim to fill the existing knowledge gaps, particularly in comparing pediatric and adult surgical outcomes, to refine treatment protocols and improve patient care in this challenging domain.

Functional Outcome Following Proximal Tibial Osteosarcoma Resection and Reconstruction by Modular Endoprosthesis

PurposeThe proximal tibia is a common location for osteosarcoma. Modular endoprosthesis is a popular reconstructive option, yet it has been associated with many complications. Our study aimed to evaluate the functional outcome and complications of proximal tibial osteosarcoma patients treated by limb salvage using modular endoprosthesis.MethodsA retrospective study of a prospective database was performed during the period between January 2000 and July 2017. Fifty-five patients with proximal tibial osteosarcoma underwent resection and modular endoprosthetic reconstruction. The functional outcome was evaluated using the Musculoskeletal tumor society scoring system and knee range of motion. Postoperative complications were classified according to Henderson classification; Type 1 (soft tissue failure), Type 2 (aseptic loosening), Type 3 (structural failure), Type 4 (infection) and Type 5 (local tumor progression).ResultsThe mean follow-up period was 71.69 ± 49.76 months. The mean musculoskeletal tumor society score was 26.5 ± 2.22; the mean range of motion was 72.63 ± 25.07, and the mean extension lag was 15.09 ± 15.38. Type 1, type 2, type 3, type 4, and type 5 complications occurred in 7.3%, 14.5%, 21.8%, 23.6%, and 5.5%, respectively. Chest metastasis developed in 10 patients (18.2%). The estimated 5-year and 10-year survival rates for the treated patients were 83.6% and 79.9%.ConclusionsProximal tibial osteosarcoma reconstruction with a modular endoprosthesis is a reliable treatment option for retaining limb function. Most complications are manageable.

Limb salvage surgery for giant cell tumours around knee joint: a single institute experience

<p class="abstract"><strong>Background:</strong> Giant cell tumours (GCTs) of bone are benign but locally aggressive tumours. The surgical treatment of GCTs in the around knee joint mainly includes curettage and bone grafting, extended curettage and cement filling, segmental resection and modular endo prosthesis reconstruction.</p><p class="abstract"><strong>Methods:</strong> Retrospective analysis of the presentation, the functional outcome following modular endoprosthetic reconstruction, prosthetic survival and the recurrence rate in 17 patients with Campanacci grade 3 GCTs involving distal femur and proximal tibia, who underwent segmental resection and modular endoprosthesis reconstruction in a single centre from 2015 to 2018. The surgery was performed according to the general principles of limb salvage surgery and modular segmental replacement was used. All stems were cemented in place. Isometric exercises and mobilization with crutches were started on 2<sup>nd</sup> postoperative day. Knee joint bending was started for proximal tibia patients after 2 to 3 weeks. Functional outcome was scored by musculoskeletal tumour society scoring (MSTS). Immediate post-operative complication like delayed wound healing, flap necrosis, wound infection, foot drop, leg length discrepancies were evaluated.<strong></strong></p><p class="abstract"><strong>Results:</strong> The average MSTS functional score was 78%.3 year prosthetic survival was 100%. None of the patients had recurrence. One patient had left lower lobe metastasis for which wedge resection was done.</p><p class="abstract"><strong>Conclusions:</strong> Segmental resection and endoprosthetic replacement has good functional outcome in patients with tumours around the knee joint. As GCTs are tumours with less chance of local and distant metastasis after complete excision, endoprosthetic prosthesis is a good treatment option after complete excision.</p>

Functional and radiologic results of extensor mechanism reconstruction methods following proximal tibial modular endoprosthetic reconstructions: Direct versus medical textile augmented reattachment

BackgroundFollowing proximal tibial resection and modular endoprosthetic reconstruction, extensor mechanism can be reconstructed with different techniques. This study compares direct reattachment (DR) with medical textile augmented reattachment (MTAR) methods in terms of functional results and radiological results. Materials and methodsFifty-five patients (34 male, 21 female) operated between 1990 and 2015 with a minimum follow up of 24 months in a single center were evaluated retrospectively. The median age was 18 years (range: 9–64). The reconstruction was performed via MTAR (polypropylene mesh, Trevira) in 23 patients and DR in 32 patients. Incidence and degree of extension lag, degree of flexion and development of postoperative patella alta were evaluated at 3, 6 and 24 months. ResultsThe mean follow up was 78.5 months. Extension lag incidence at 24 months was 71.9% in the DR group compared with 43.5% in the MTAR group (P < 0.05).Theextensionlagratiosat 24 months in DR was 0–5° in 8.7% (n = 2), 6–10° in 21.7% (n = 5), 11–15° in 17.4% (n = 4) and > 15° in 52.2% (n = 12), respectively. Extension lag ratios at 24 months in MTAR were 0–5° in 12.5% (n = 4), 6–10° in 6.3% (n = 2), 11–15° in 6.3% (n = 2) and > 15° in 6.3% (n = 2). The mean MSTS score in DR group was 20.7 compared with 23.2 in the MTAR group (P = 0.008). ConclusionMTAR is associated with a lower incidence as well as a lower degree of extension lag. The flexion range and the incidence of patella alta are not statistically different between the groups. MSTS scores of MTAR group are significantly higher than DR group at 2-year follow up.

Survival and outcomes of modular endoprosthetic reconstruction of the proximal femur for primary and non-primary bone tumors: Single institutional results

PurposeThis study assessed implant survival and dislocation following proximal femur tumor endoprosthetic replacement. MethodsThirty-eight procedures were performed between 2005 and 2019. The cumulative incidence of implant revision was calculated with death as a competing risk. ResultsThe majority of endoprostheses were bipolar hemiarthroplasty (n = 33, 86.8%). The cumulative incidence of revision was 14.6% (95% CI, 3.2%–34.1%) at five years. Dislocation occurred in 7.9% (n = 3) of hips at a mean (SD) 44 ± 35.2 days. ConclusionsProximal femur tumor endoprosthetic replacement is a durable option that tends to outlive patients. Strict postoperative bracing may lower dislocation rates. Level of evidenceIII. Retrospective Study.

Limb salvage surgery of primary and metastatic bone tumors of the lower extremity: Functional outcomes and survivorship of modular endoprosthetic reconstruction.

The study was aimed to determine the survivorship and functional outcomes of modular endoprosthetic reconstruction in the management of primary and metastatic bone tumors of the lower limbs and to investigate the rate and causes of implant failure. A total of 84 limbs of 82 patients (49 male, 33 female; mean age=48 years, age range=13-78 years) with a minimum follow-up of 12 months in whom resection and modular endoprosthetic reconstructions were performed for primary or metastatic bone tumors of the lower extremity were retrospectively reviewed and included in the study. The mean follow-up was 43 (range=13-119) months. Functional status was assessed using the Musculoskeletal Tumor Society (MSTS) scoring system at the final follow-up. Implant survival was defined as the time from implantation until partial or complete exchange of the prosthesis secondary to mechanical or nonmechanical causes or amputation. The effects of the anatomical site on functional scores and implant survival were statistically analyzed. Additionally, the effects of diagnosis and adjuvant treatments on functional scores, implant survival, and failure rates were investigated. At the time of the study, 55 patients were still alive with a mean follow-up of 48 (range=15-119) months. The mean MSTS scores resulting from the final follow-up of all patients and of those surviving were 87.9% (range=16%-100%) and 86.8% (range=16%-100%), respectively. Overall implant survival was 95.2%, 89.2%, 87%, and 87% at 1, 2, 3, and 4 years, respectively. Statistically, both functional scores and implant survival analysis in different anatomical sites were found similar. In 15 of the patients (17.8%), endoprosthetic reconstructions had failed. The causes of failure were soft tissue failure (dislocation) in 5 patients, infection in 5, structural/mechanical failure in 2, local recurrence in two, and aseptic loosening in one. The diagnosis and receiving preoperative and/or postoperative adjuvant treatment did not affect functional scores, implant survival or failure rates. The results of this study have shown that modular endoprosthetic replacement can provide satisfactory functional results and a durable mid-term limb salvage option in the management of patients with primary and metastatic bone tumors of the lower limbs. Level IV, Therapeutic Study.

What sports activity levels are achieved in long-term survivors with modular endoprosthetic humerus reconstruction following primary bone sarcoma resection?

SummaryBackgroundThe aim of the study was to assess (1) sports activity, (2) sports involving the upper extremities, (3) functional outcome and (4) sports-related complications of long-term survivors of primary malignant bone tumors of the proximal humerus.MethodsA total of 18 patients with an endoprosthetic reconstruction for primary malignant bone sarcoma of the proximal humerus (8 male, 10 female, mean age 19.9 ± 8.4 years, range 7.8–37.4 years) with an average follow-up of 18.1 ± 7.4 years (range 6.7–29.8 years) were included. The type of sport, frequency, duration of each sport session and the University of California, Los Angeles (UCLA) activity score were assessed before surgery, at 1 year, 3 years and at the latest follow-up. Functional outcome was assessed by the Toronto extremity salvage score (TESS).ResultsThe mean UCLA activity score decreased from 8.0 (±1.3, range 5–9) preoperative to 4.2 (±1.7, range 3–8) at 1‑year follow-up (p < 0.05). After 3 years it increased to 5.1 (±1.75, range 3–8) and further to 7 (±1.8, range 4–9) at the last follow-up. The mean postoperative TESS was 80.8 (±6.4, range 75.7–91.4) at the latest follow-up. Patients who were initially more active without reconstruction including a synthetic mesh were more likely to develop soft tissue complications accompanied by proximal endoprothesis migration.ConclusionPatients with a modular endoprosthetic reconstruction of the humerus following primary bone sarcoma resume participation in sports. Regarding the low incidence of periprosthetic infections, utilization of a synthetic mesh for reconstruction to prevent soft tissue complications in active patients should be considered.

Preliminary results of reconstruction of proximal humeral bone loss with a reverse total shoulder prosthesis using a modular endoprosthetic reconstruction system: a case series

Background: Osteoarticular allografts and allograft-prosthesis composites have decreased some complications but have introduced others, prompting development of implants that combine a reverse total shoulder arthroplasty (RTSA) prosthesis with a modular endoprosthetic reconstruction system. Methods: Data were collected prospectively from two institutions for all patients with massive proximal humeral bone loss who had reconstruction with RTSA using a single modular endoprosthetic system. The primary outcome measure was failure of the reconstruction, defined as need for revision surgery or radiographic evidence of component failure. Preoperative and postoperative functional outcomes and patient-reported outcomes, determined through preoperative and postoperative Quick Disabilities of Arm, Shoulder and Hand (quickDASH) scores, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores, and visual analog scores (VAS), were compared. Results: Seven female and five male patients met inclusion criteria. The most common reason for proximal bone loss was failure of a previous arthroplasty procedure (six patients). Average forward flexion and internal rotation improved significantly, as did the average quickDASH, ASES and VAS scores. Failure of humeral component fixation occurred in three patients. Conclusions: Early results show that a RTSA prosthesis using a modular endoprosthetic reconstruction system is a viable option for massive proximal humeral bone loss. Further studies are needed to investigate longevity and longer-term outcomes. Level of Evidence: Level IV.

Results of modular endoprosthetic reconstruction of periacetabular bone defects in patients with tumors of the acetabulum and hip joint

Introduction. surgical treatment of patients with pelvic bone tumors, in particular periacetabular tumors, remains challenging. There are many different reconstruction options after resection of these tumors. These include allo- and autografts, megaprosthesis, saddle endoprosthesis, custom-made endoprosthesis, 3D printing endoprosthesis, and femur transposition with the formation of neo-arthrosis. However, all of them are characterized by technical complexity and high risk of postoperative complications. There is still no standard procedure for reconstruction after resection of malignant periacetabular tumors. To date, modular endoprosthesis is a well-established reconstructive device in orthopaedic oncology to manage wide bone resections. Modular systems provide patient-specific endoprostheses that could be modified during surgery. In this article, we present the results of modular acetabular endoprostheses in the treatment of patients with periacetabular tumors. Material and Methods. From 2011 to 2018, 30 patients underwent modular endoprosthetic reconstruction after periacetabular resection. There were 13 (43 %) male and 17 (57 %) female patients aged from 23 to 63 years (median age 45 years). Primary malignant bone tumors were detected in 19 (63 %) patients, giant cell tumor in 5 (17 %), local soft tissue sarcoma in 1 (3 %), solitary metastases of kidney cancer in 2 (7 %) and recurrent sarcoma after previous surgical treatment in 3 (10 %) patients. Results. The average duration of surgery was 310 minutes (range: 145-520 minutes), blood loss was 5520 ml (range: 600-20000 ml). The median follow-up time was 36 months. Histological examination revealed a positive resection margin in 3 (10 %) patients. At a follow-up from 6 to 40 months, disease progression was detected in 10 (33 %) patients. Eight (27 %) patients died on disease progression. Complications of various types were diagnosed in 11 (37 %) patients. Infectious complications were the most common (30 % of patients). The average value of the functional assessment by the MSTS scale was 59 % (15-82%). Conclusion. Modular endoprosthetic replacement for tumors of the acetabulum and hip joint is a promising surgical technique allowing adequate functional results to be achieved.

Proximal tibia modular endoprosthetic replacement. Analysis of complications

The reconstruction of proximal tibial by using modular endoprosthetics is a complex surgical procedure, accompanied by a significant number of complications (40–70 %) in the period of follow up of 5–15 years.Objective: to analyze the primary complications of modular endoprosthetic reconstruction of proximal tibial.Methods: the results of surgical interventions performed on 47 patients with PT tumor lesions (20 men (42.6 %) and 27 women (57.4 %), age from 12 to 74 years) were evaluated. The patients were divided into two groups: I (35 people) — primary modular endoprosthetics after removal of the tumor, II (12) — revision.Results: in the period from 3 weeks to 13 years after the establishment of a modular endoprosthesis due to complications, 18 (38.2 %) patients underwent revision surgeries. The implanted endoprosthesis was removed in 12 cases (25.5 %): in group I — 9 (25.7 %), in II — 3 (25 %). Due to tumor recurrence, 2 (4.26 %) myofascioplastic amputations were performed. Complications associated with the insufficiency of soft tissues (type I) were observed in 3 (6.3 %) people: in group I — 1 (7.6 % of all complications in the group), in II — 2 (40 %). Aseptic instability (type II) was detected in one case of group I (7.6 % of all group complications) 6 years after primary endoprosthesis. Periprosthetic infection (type IV) developed in periods from 12 days to 4 years in 12 patients (70 % of all complications): in group I — 9 (52.9 %), in II — 3 (17.6 %). Local recurrence of a tumor lesion (V type) was detected in 2 (11.7 % of all complications) people of group I after 6 months. and 3 years after surgery.Conclusions: in patients with malignant tumors of proximal tibial, the technique of replacing post-resection defects with modular endoprostheses is justified, since it provides 61.8 % positive results.

Current review of surgical management options for extremity bone sarcomas.

Modern surgical management of extremity bone sarcomas is governed by limb-sparing surgery combined with adjuvant and neoadjuvant chemotherapy.All the resection and reconstruction techniques have to achieve oncologic excision margins, with survival rates and functional results superior to amputation.The main reconstruction techniques of bone defects resulted after resection are: modular endoprosthetic reconstruction; bone graft reconstruction; bone transport; resection arthrodesis; and rotationplasty.Oncologic resection and modular endoprosthetic reconstruction are the generally approved surgical options adopted for the majority of cases in major specialized bone sarcoma centres.Good basic principles, efficient multidisciplinary approach and sustained research in the field can provide a better future for the challenge posed by extremity bone sarcoma treatment.Cite this article: EFORT Open Rev 2019;4:174-182. DOI: 10.1302/2058-5241.4.180048

Which factors are associated with the functional recovery in patients undergoing endoprosthetic knee reconstruction following bone tumour resection? \u2013 A observational study

BackgroundThe aim of the present study was to explore whether control of balance and other factors were associated with functional recovery and walking performance in the short term in a group of patients receiving modular knee endoprosthetic reconstruction following bone tumour resection in order to provide effective suggestions for a new rehabilitation protocol.MethodsA cross-sectional study was carried out in the chemotherapy ward of an Italian hospital specialized in bone cancer. All patients consecutively treated using a modular knee endoprosthetic between January 2013 and February 2014 were included in the study. One year after surgery, various measuring instruments were used to assess the functional outcome achieved: Musculoskeletal Tumor Society rating scale, Toronto Extremity Salvage Score and specific motor tests of gait, such as gait speed and resistance. Data concerning the variables involved are as follows: bone resection, knee joint range of motion, quadriceps muscle strength and posture control. Statistical tests included correlation analysis (Pearson and Spearman correlation).ResultsBalance control was significantly correlated to all the gait tests performed. Age, duration of chemotherapy and strength of the knee extensor muscles also showed a correlation. Conversely, joint range of motion and resection percentage did not show a significant correlation.ConclusionsRehabilitation in patients undergoing knee joint reconstruction due to cancer should include balance control exercises, which involve not only the treated limb but address the entire sensory and motor system. This extends beyond the concept of treatment aimed at improving individual functions such as joint range of motion and muscular strength.

Treating Humeral Bone Loss in Shoulder Arthroplasty: Modular Humeral Components or Allografts.

Reconstructing proximal humeral bone loss in the setting of shoulder arthroplasty can be a daunting task. Proposed techniques include long-stemmed humeral components, allograft-prosthesis composites (APCs), and modular endoprosthetic reconstruction. While unsupported long-stemmed components are at high risk for component loosening, APC reconstruction techniques have been reported with success. However, graft resorption and eventual failure are significant concerns. Modular endoprosthetic systems allow bone deficiencies to be reconstructed with metal, which may allow for a more durable reconstruction.

Outcome after Reconstruction of the Proximal Tibia--Complications and Competing Risk Analysis.

Background and ObjectivesThe proximal tibia (pT) is a common site for bone tumors. Improvements in imaging, chemotherapy and surgical technique made limb salvage surgery the treatment of choice. Yet, reconstructions of the pT have been associated with less favorable outcome compared to other parts of the extremities. The aim of this study was to evaluate the outcome of patients with a modular endoprosthetic reconstruction of the pT.MethodsEighty-one consecutive patients with an average age of 29 years underwent endoprosthetic reconstruction of the pT. Postoperative complications were categorized according to the ISOLS classification, and revision-free survival until first complication (any Type 1–5), soft tissue failure (Type 1), aseptic loosening (Type 2), structural failure (Type 3), infection (Type 4), and local tumor progression (Type 5) was estimated by using a Fine-Gray model for competing risk analyses for univariate and multivariable regression with Firth’s bias correction.ResultsA total of 45 patients (56%) had at least one complication. Cumulative incidence for complication Types 1 to 5 at 5 years with death and amputation as competing events revealed a risk of 41% for the first complication, 14% for Type 1, 16% for Type 2, 11% for Type 3, 17% for Type 4, and 1% for Type 5.ConclusionDespite inclusion of amputation and death as strong competing events, pT replacements are still associated with a high risk of postoperative failures. The results suggest that infection and soft tissue failures (Type 1 and 5) seem to depend from each other. Sufficient soft tissue reconstruction and closure allow better function and reduce the risk of infection as the most prominent complication. The use of a rotating hinge design has significantly reduced structural failures over time.

Indications and limits for modular endoprosthetic reconstruction by MUTARS implants in patients with malignant bone tumor (literature review)

Сьогодні модульні пухлинні ендопротези широко використовують для заміщення післярезекційних кістково-суглобових дефектів. Майже будь-який дефект кістки (навіть тотальний плечової або стегнової) чи суглоба можна замістити з високими післяопераційними функціональними результатами та відносно невисокими для індивідуального ендопротезування матеріальними затратами. При цьому зберігається техніка аблаційного видалення пухлини. За останні 30 років п’ятирічна виживаність мегаендопротезів збільшилась від 20 до 85 %. Нині рівень ускладнень після модульного ендопротезування знизився, але порівняно з первинним ендопротезуванням суглобів залишився досить високим. Разом з локальними рецидивами пухлин у ділянці хірургічного втручання найскладнішими є інфекційні ускладнення. Розвиток хірургічної техніки та матеріалознавства значно поширюють показання до органозберігальних хірургічних втручань та дають змогу використовувати модульні ендопротези в більшості клінічних випадків. Найпоширенішими показаннями для мегаендопротезування є дефекти кісток після видалення злоякісних пухлин верхньої і нижньої кінцівок. Залучення до пухлинного процесу магістральних судин ще залишається протипоказанням для збереження кінцівки, але вже можливе використання судинної пластики для реконструкції кінцівки з хорошими онкологічними і функціональними результатами. Сьогодні функціональні результати після сучасного модульного пухлинного ендопротезування є доволі високими. Їх зазвичай оцінюють за шкалою Enneking. У поданому огляді представлені результати використання модульної системи пухлинних ендопротезів MUTARS виробництва компанії Implantcast (Німеччина) з обговоренням показань та протипоказань, ускладнень та функціональних результатів таких операцій. Робота містить рекомендації щодо хірургічної техніки та післяопераційного ведення цієї категорії хворих.

Reconstruction with modular hemipelvic prosthesis for the resection of solitary periacetabular metastasis

The outcomes of patients with solitary metastasis around the acetabulum who received en bloc resection and reconstruction are unclear. The purpose is to evaluate the oncologic results, complications, and functional outcomes in these patients. Fifteen patients who underwent periacetabular resection and modular endoprosthetic reconstruction were reviewed retrospectively. Eleven patients were alive and four had died of their respective diseases. The mean follow-up time for the living patients and the non-surviving patients was 32 and 11 months, respectively. One of the three patients presented with local recurrence received hindquarter amputation. Five patients with superficial wound problem were treated with debridement and were healed eventually. Two patients who had hip dislocation received closed reduction. Pain was relieved in most patients, and ten patients were able to walk outside their house. The average MSTS 93 score was 20.9 of a total of 30 points (69.7%). When evaluated according to the modified Allan scoring system, postoperative scores on pain, independence, and mobility had significant improvement. En bloc tumor resection and reconstruction with modular hemipelvic prosthesis in patients who had a solitary periacetabular metastasis can provide long-term survive, tumor local control, low complication rate, and good functional recovery.

Management of septic complications following modular endoprosthetic reconstruction of the proximal femur

In a retrospective single-centre study 170 consecutive patients were included who received a Kotz modular prosthesis after resection of bone tumours of the proximal femur to evaluate the management of prosthetic infection. Infection occurred in 12 of 166 patients available for follow-up (six males; six females; mean age, 47years; range, ten to 75years) after a mean of 39months (range, one to 166months; infection rate, 7.2%). Mean follow-up was 54months (range, four to 200months). One patient died of septic shock. Two patients were treated by wound revision only. Treatment of infection in the remaining patients was one-stage revision in eight and hip disarticulation in one. Infection control by one-stage revision was achieved in five of eight patients; re-infection occurred in three patients and was successfully treated by further revision in all of them. The overall success rate for controlling infection was 83.3%.

Survivorship and clinical outcome of modular endoprosthetic reconstruction for neoplastic disease of the lower limb

Survivorship and clinical outcome of modular endoprosthetic reconstruction for neoplastic disease of the lower limb

Survivorship and clinical outcome of modular endoprosthetic reconstruction for neoplastic disease of the lower limb

We reviewed retrospectively the results in 211 consecutive patients who had undergone limb salvage for bone neoplasia with endoprosthetic reconstruction of the proximal femur (96), distal femur (78), proximal tibia (30) and total femur (7). Their mean age was 50 years (11 to 86) and the mean follow-up period was 37.3 months (1 to 204). A total of 35 (16.6%) prostheses failed. Overall, implant survival was 78% (95% confidence interval (CI) 0.29 to 0.54) at five years, 60% (95% CI 0.93 to 2.35) at ten years and 60% (95% CI 1.27 to 3.88) at 15 years. Survivorship of the limb was 97.6% (95% CI 1.73 to 3.35) at ten years. The gender, age, diagnosis and location of the tumour were not prognostic variables for failure. Modular endoprosthetic replacement in the lower limb is a durable long-term reconstructive option, with the implants generally outlasting the patient.

Knee Proprioception in Patients with Osteosarcoma Around the Knee After Modular Endoprosthetic Reconstruction

Proprioception as an outcome for patients with osteosarcoma who have undergone modular endoprosthetic knee reconstruction has not been studied, as far as we know. The primary purpose of the present study was to understand the differences in knee proprioception between this patient population and control subjects. We also compared differences in proprioception between patients with tumors at different sites and between patients who had different proportions of bone length excised. We evaluated twenty patients who had undergone a wide resection of a tumor about the knee followed by reconstruction with a modular endoprosthesis. The mean age of the patients was 21.7 years. The patients were grouped according to tumor site, i.e., the distal part of the femur or the proximal part of the tibia; they were also grouped according to the length of resected bone (<40% or >or=40% of the length of the bone). Another twenty age-matched control subjects were recruited for this study. Knee proprioception was evaluated by comparing active and passive angular repositioning of the involved limb and the normal limb in the patients and the dominant limb in the central subjects. The absolute matching error of active and passive repositioning was 2.7 degrees +/- 2.1 degrees and 2.9 degrees +/- 2.2 degrees , respectively, for knees treated operatively and 3.2 degrees +/- 2.1 degrees and 2.1 degrees +/- 1.3 degrees , respectively, for the dominant knees in the control subjects. The differences between the operatively treated knees and the control knees were not significant (p > 0.05). There was also no significant difference in proprioception between the patients with a distal femoral tumor and those with a proximal tibial tumor (p > 0.05). The proprioception of the patients with a greater length of bone resected was significantly worse in both lower extremities than that of patients with a shorter resected length (p = 0.016 for the normal side and p = 0.025 for the involved side). The proprioception of the involved knees in the patients with osteosarcoma who had modular endoprosthetic reconstruction was not found to be different from the normal knees or the knees in the control subjects. On the basis of our data, we found that proprioception is probably not influenced by the tumor site. Conversely, resection length appears to be an important factor. These study findings may be used as a reference for knee proprioception in patients with osteosarcoma who have a modular endoprosthetic knee reconstruction.