The long-term results of endoprosthetic replacement of the proximal tibia for bone tumours

Outcomes of distal femoral replacement versus internal fixation for metastatic bone diseases of the distal femur

Background

In clinical practice, internal fixation (IF) is a commonly utilized technique for metastatic bone disease (MBD) to the distal femur. Additionally, distal femoral reconstruction (DFR) has shown to be an effective surgical technique for primary tumors and MBD in the distal femur. The existing body of research comparing these methods has not focused on MBD or pathological fractures and thus does not guide surgical approach in the case of distal femoral MBD.

Methods

A multi-institutional retrospective review of musculoskeletal oncology patients treated surgically with IF (n = 29) or DFR (n = 34) for distal femoral MBD between 2005 and 2023. Overall survival, revision risk, and functional status were assessed.

Results

5-year patient overall survival was 47.9 % (CI, 29.5-77.6 %) and 46.6 % (CI, 31.5-68.8 %), for DFR and IF, respectively (p = 0.91). After competing risk analysis, the 5-year risk of implant revision for DFR was 18 % (95 % CI: 5.1-37 %) and 11 % for IF (95 % CI: 2.4-28 %) (p = 0.3). DFR had longer operative times (p = 0.002), higher blood loss (p < 0.001), and greater postoperative (p = 0.006) complications than IF. In addition, patients undergoing DFR had more distal lesions than patients who received IF (p = 0.003).

Conclusion

Despite similar overall survival and revision rates, IF may be preferable for patients due to its shorter operative time and lower rates of complication than DFR. However, specific anatomic location in the distal femur must be considered prior to deciding which procedure is optimal.

Proximal tibial replacement with megaprosthesis in the setting of proximal tibial nonunion: A case report

Background

Fracture nonunion is a major concern among an orthopaedic patient population, especially in those who have sustained traumatic fractures involving the tibia. Strong risk factors for nonunion include age, smoking history, and a poor diet. The incidence of nonunion also increases with each additional failed surgical intervention.

Methods

Our retrospective case study involved 56-year-old woman with a history of chronic low back pain, osteopenia, malnutrition, smoking, marijuana use, and alcohol use, who presented with a proximal tibia fracture after a fall, initial treatment included temporization with multiplanar external fixation and subsequent internal fixation. Five weeks later, she presented with atrophic nonunion. She subsequently underwent multiple unsuccessful surgeries to address her nonunion, including open repair with bone grafting and multiplanar external fixation for bone transport. Ultimately, the nonunion was addressed by proximal tibia replacement with megaprosthesis with excellent clinical results.

Results and conclusion

Replacement of a proximal tibia with megaprosthesis is a viable option for limb salvage, especially when all alternative treatments have been unsuccessful.

Coverage of lateral soft tissue defects with sartorius muscle flap after distal femoral replacement for malignant bone tumors

INTRODUCTION

To prevent infection after limb-sparing surgery for primary malignant bone tumors, it is important to cover the megaprosthesis with muscle tissue that has sufficient blood flow. Coverage with a lateral gastrocnemius flap has been reported in cases of distal femoral replacement in which the vastus lateralis and vastus intermedius muscles have been resected; however, the risk of peroneal nerve palsy is reportedly high because the muscle flap passes near the peroneal head. This study was performed to examine the postoperative outcomes of patients with primary malignant bone tumors of the distal femur who underwent wide resection (including the vastus lateralis and vastus intermedius muscles) followed by reconstruction with a megaprosthesis and coverage of the lateral side of the prosthesis with a sartorius muscle flap.

METHODS

We retrospectively analyzed three patients who underwent reconstruction with a megaprosthesis after wide resection of a primary malignant bone tumor of the distal femur involving the vastus lateralis and vastus intermedius muscles and reconstruction of the soft tissue defect on the lateral side of the prosthesis with a sartorius muscle flap.

RESULTS

The average defect size was 6 × 13 cm, the average time required for a sartorius muscle flap was 100 min, and the average implant coverage was 93%. The average postoperative follow-up period was 35 months, during which no postoperative complications such as infection, skin necrosis, or nerve palsy occurred.

DISCUSSION

The distally based sartorius muscle flap is easy to elevate in the supine position, has minimal functional loss after harvesting, and has minimal risk of nerve palsy. It can be advocated as the first option for coverage of soft tissue defects lateral to distal femoral replacement.

The survival and complication profiles of the Compress® Endoprosthesis: A systematic review and meta-analysis

Background/purpose

This study aimed to summarize the survival and complication profiles of the compress® endoprosthesis (CPS) through a systematic review and meta-analysis.

Methods

Online databases (PubMed, EMBASE and Web of Science) were searched from inception to November 2023. Trials were included that involved the use of CPS for endoprosthetic replacement in patients with massive segmental bone defects. Patients' clinical characteristics and demographic data were extracted using a standardized form. The methodological quality of included 13 non-comparative studies was assessed on basis of the Methodological Index for Non-Randomized Studies (MINORS). All the available Kaplan-Meier curves in the included studies were digitized and combined using Engauge-Digitizer software and the R Project for Statistical Computing.

Results

The meta-analysis of thirteen included studies indicated: the all-cause failure rates of CPS were 26.3 % after surgery, in which the occurrence rates of aseptic loosening were 5.8 %. And the incidences of other complications were as follows: soft tissue failure (1.8 %), structure failure (8.2 %), infection (9.5 %), tumor progression (1.1 %). The 1-, 4-, and 8-year overall survival rates for all-cause failure with 95 % CI were 89 % (86 %-92 %), 75 % (71 %-79 %) and 65 % (60 %-70 %), respectively. The estimated mean survival time of all-cause failure was 145 months (95 % CI, 127-148 months), and the estimated median survival time of all-cause failure was 187 months (95 % CI, 135-198 months). The 1-, 4-, and 8-year overall survival rates of aseptic loosening with 95 % CI were 96 % (94 %-98 %), 91 % (87 %-95 %) and 88 % (83 %-93 %), respectively. The estimated mean survival time of aseptic loosening was 148 months (95 % CI, 137-153 months).

Conclusion

CPS's innovative spring system promotes bone ingrowth by providing immediate and high-compression fixation, thereby reducing the risk of aseptic loosening caused by stress shielding and particle-induced osteolysis. CPS requires less residual bone mass for reconstructing massive segmental bone defects and facilitates easier revision due to its non-cemented fixation. In addition, the survival rate, estimated mean survival time, and complication rates of CPS are not inferior to those of common endoprosthesis.

Incidence and risk of surgical site infection/periprosthetic joint infection in tumor endoprosthesis-data from the nationwide bone tumor registry in Japan

BACKGROUND

Surgical site infection (SSI)/periprosthetic joint infection (PJI) is a devastating complication in limb salvage surgery with endoprosthesis reconstruction for malignant bone tumors. The main bottleneck for data collection and analysis for the status of SSI/PJI in tumor endoprosthesis is the low absolute case numbers of this rare cancer. The accumulation of many cases is possible by administrating nationwide registry data.

METHODS

The data on malignant bone tumor resection with tumor endoprosthesis reconstruction were extracted from the Bone and Soft Tissue Tumor Registry in Japan. The primary endpoint was defined as the need for additional surgical intervention for infection control. The incidence of postoperative infection and its risk factors were analyzed.

RESULTS

A total of 1342 cases were included. The incidence of SSI/PJI was 8.2%. The incidence of SSI/PJI in the proximal femur, distal femur, proximal tibia, and pelvis were 4.9%, 7.4%, 12.6%, and 41.2%, respectively. Location in the pelvis or proximal tibia, tumor grade, indication of myocutaneous flaps, and delayed wound healing proved to be independent risks for SSI/PJI, whereas age, sex, previous surgery, tumor size, surgical margin, application of chemotherapy and radiotherapy were not significant.

CONCLUSIONS

The incidence was equal to those in previous studies. The result reconfirmed the high incidence of SSI/PJI in pelvis and proximal tibia cases and cases with delayed wound healing. Novel risk factors such as tumor grade and application of myocutaneous flaps were marked. The administration of nationwide registry data was informative for the analysis of SSI/PJI in tumor endoprosthesis.

What Factors Are Associated With Stem Breakage in Distal Femoral Endoprosthetic Replacements Undertaken for Primary Bone Tumors?

BACKGROUND

The advantages of distal femoral replacement prostheses for reconstructions after tumors are well known; one such implant, the Global Modular Replacement System (GMRS), has been widely used since 2003. Although implant breakage has been reported, the frequency of this event has varied across different studies.

QUESTIONS/PURPOSES

(1) What percentage of patients who underwent distal femur resection and replacement using the GMRS for primary bone tumors at one center experienced stem breakage? (2) At what timepoints did these breakages occur, and what factors were common among the stems that broke?

METHODS

We performed a retrospective study of all patients who underwent distal femur resection and replacement using the GMRS for a diagnosis of primary bone sarcoma by the Queensland Bone and Soft-tissue Tumor service from 2003 to 2020 who had a minimum of 2 years of follow-up. Standard follow-up for primary bone sarcoma involves radiographic imaging of the femur at 6 weeks and 3 months postoperatively and yearly thereafter. From a chart review, we identified patients with femoral stem breakage. Patient and implant details were recorded and analyzed. A total of 116 patients had undergone a distal femoral replacement with the GMRS prosthesis for primary bone sarcoma; however, 6.9% (eight of 116 patients) died before completing the 2-year follow-up period and were excluded. Of the remaining 108 patients, 15% (16 patients) had died at the time of this review; however, given that they completed the 2-year follow-up period and did not experience stem breakage, they were included. Furthermore, 15% (16 patients) were considered lost to follow-up and excluded because they have not been seen in the past 5 years but were not known to have died or experienced stem breakage. This left 92 patients for analysis.

RESULTS

Stem breakages were identified in 5.4% (five of 92) of patients. All stem breakages occurred in stem diameters 11 mm or less with a porous body construct; the percentage of patients with breakage in this group was 16% (five of 31). All patients with stem fracture demonstrated minimal ongrowth to the porous coated body. The median time to stem fracture was 10 years (range 2 to 12 years); however, two of the five stems broke within 3 years.

CONCLUSION

We recommend the use of a larger-diameter GMRS cemented stem (> 11 mm), and either the line-to-line cementing method or an uncemented stem from an alternative company should be considered in order to achieve this larger stem in smaller canals. If a stem less than 12 mm in diameter must be used or there is evidence of minimal ongrowth, then close follow-up and prompt investigation of new symptoms should occur.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

What to improve: Results of fixed-hinge knee endoprosthesis reconstructions over 40 years in a single tumor center

INTRODUCTION

Over the past decades, numerous structural changes in implants, medical treatments, and surgical techniques have been made for Malignant Bone Tumors (MBT) around the knee. However, the overall care improvement is still unclear. The method is crucial when analyzing outcomes in surveys involving tumors, and a thorough assessment of the mortality is mandatory because death acts as competing event. The aims of this study were: 1) a comprehensive and longitudinal assessment of the revisions with an extensive follow-up and adequate methods; 2) a complete mortality review to consider competing risks.

HYPOTHESIS

The hypothesis was that some prosthesis's structural improvements were made while the surgical toll increased as well as an improvement of mortality was also expected.

MATERIAL AND METHODS

Analyses were performed on 248 patients with MBT (mean follow-up was 8.7 years, surgeries between 1972 and 2017). Three prosthesis models were successively used over time: 120 Guepar (older model), 42 Tornier, and 86 Stanmore (more recent model). The primary outcome was the assessment of revisions sorted out according to Henderson: type-1 soft-tissue failures or instability, type-2 aseptic loosening, type-3 structural failures, type-4 periprosthetic infections, type-5 tumoral progression. Death and amputations were considered as competing events. An extensive assessment of mortality was performed by merging the dataset with the French register of Deaths (INSEE). Cumulative probabilities were computed at 2, 5, 10, and 15 years and compared with Gray's tests.

RESULTS

The overall 5-year survival was, 80% (95% CI: 73-87) for Guepar, 69% (95% CI: 56-84) for Tornier, and 71% (95% CI: 62-82) for Stanmore (p=0.4). The 5-year cumulative risks for type-1 were 5% (95% CI: 1-9), 9% (95% CI: 0-18), and 17% (95% CI: 9-25) for Guepar, Tornier, and Stanmore, respectively (p=0.01). The 15-year cumulative risks for type-2 were 22% (95% CI: 15-39), 8% (95% CI: 0-17) and 8% (95% CI: 2-14) for Guepar, Tornier, and Stanmore, respectively (p=0.10). Ten patients had an implant failure, nine Guepar, and one Tornier. The 5-year cumulative risks for type-4 were 7% (95% CI: 2-12), 19% (95% CI: 7-31), and 12% (95% CI: 5-18) for Guepar, Tornier, and Stanmore, respectively (p=0.08). There were 29 tumoral progressions; the 15-year risks were 16% (95% CI: 2-22), 2% (95% CI: 0-7%), and 12% (95% CI: 4-19%) for Guepar, Tornier, and Stanmore, respectively (p=0.08). No difference whatsoever was found between the proximal tibial and distal femur.

CONCLUSION

There were some improvements in prosthesis design (forged steel instead of cast steel) and probably also in cemented stem fixation, but not in prosthetic joint infection and local recurrence over forty years. The overall mortality did not change significantly over the last 40 years amongst this specific cohort of patients who benefited from a hinge reconstruction prosthesis.

LEVEL OF EVIDENCE

III; comparative case series with sensibility analysis.

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

PURPOSE

The 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.

METHODS

A 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).

RESULTS

The 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%.

CONCLUSIONS

Proximal tibial osteosarcoma reconstruction with a modular endoprosthesis is a reliable treatment option for retaining limb function. Most complications are manageable.

Revision Total Knee Arthroplasty Utilizing Threaded Pins in Cement for Tibial Bone Loss

Introduction: a primary goal in revision total knee arthroplasty is to recreate and restore near-normal knee biomechanics by reapproximating the native anatomy. Tibial bone loss poses a challenge for surgeons. Bone cement, bone allograft, screws-in-cement, metaphyseal sleeves or cones, and metallic augments are some options for addressing bony deficiency, with endoprosthetic proximal tibia replacement a consideration for the most severe cases. Case Description: we present a case for the novel use of threaded Steinmann pins augmented with cement to reconstruct a massive tibial metaphyseal cortical defect during revision knee arthroplasty. A 76-year-old male presented with an infected primary total knee arthroplasty using MSIS (Musculoskeletal Infection Society) criteria and underwent a standard two-stage revision total knee arthroplasty once the knee was confirmed sterile. Intraoperatively, significant posteromedial and metaphyseal tibial bone loss was identified. In order to avoid proximal tibial replacement and the extensor mechanism complications seen with these, coupled with obligate gastrocnemius flap, a metaphyseal cone was utilized in the proximal tibia with four vertical threaded Steinmann pins spaced approximately 1 cm apart at its periphery, subsequently cut flush with the level of the cone after cementation to recreate the tibial cortex. The patient's function and range of motion continue to improve with no evidence of structural complication at 2.5 years of follow-up. Discussion: the implementation of threaded Steinmann pins was utilized in this case to stabilize a cemented metaphyseal cone in the revision of an infected total knee with significant tibial bone loss. The threaded property may help prevent migration of these pins in comparison to smooth pins. Creation of a stable platform in a revision total knee arthroplasty poses a substantial challenge in the context of significant bone loss, and our case depicts a good short-term outcome and another option for surgeons to consider before moving toward endoprostheses.

Novel reconstruction method by mega-prosthesis wrapped with vancomycin-containing cement after resection of malignancies

To introduce wrapping vancomycin-containing cement around a mega-prosthesis (MP) as a novel method to prevent prosthetic joint infection after reconstruction surgery for malignant bone and soft tissue tumors. Five patients with malignant bone and soft tissue tumors treated at our hospital from April 2009 to December 2019 were included. The average age was 71.4 years. Four males and one female were included. Three patients had a bone tumor, and two had a soft tissue tumor. Three right thighs and two left femurs were affected. These tumors were identified histologically as undifferentiated pleomorphic sarcoma, spindle cell sarcoma, diffuse large cell B-cell lymphoma, metastasis of renal cancer, and metastasis of lung cancer. All patients underwent tumor resection and reconstruction with a MP. In all cases, vancomycin-containing cement (2 g/40 g) was wrapped around the implant at the extension. The average follow-up period was 30.4 months. We surveyed whether infection occurred after surgical treatment. We also investigated the Musculoskeletal Tumor Society score and clinical outcome. We observed no postoperative infection. One case of local recurrence was observed, and a hip dissection was performed. The Musculoskeletal Tumor Society score was 79.26 ± 1.26 (mean ± standard deviation) (range: 76-80.3). Three patients remained disease-free, one survived but with disease, and one died of disease. Wrapping vancomycin-containing cement around the MP may be a useful method of preventing postoperative joint infections.

Endoprosthetic replacement of the proximal tibia for oncological conditions

Aims

The proximal tibia (PT) is the anatomical site most frequently affected by primary bone tumours after the distal femur. Reconstruction of the PT remains challenging because of the poor soft-tissue cover and the need to reconstruct the extensor mechanism. Reconstructive techniques include implantation of massive endoprosthesis (megaprosthesis), osteoarticular allografts (OAs), or allograft-prosthesis composites (APCs).

Methods

This was a retrospective analysis of clinical data relating to patients who underwent proximal tibial arthroplasty in our regional bone tumour centre from 2010 to 2018.

Results

A total of 76 patients fulfilled the inclusion criteria and were included in the study. Mean age at surgery was 43.2 years (12 to 86 (SD 21)). The mean follow-up period was 60.1 months (5.4 to 353). In total 21 failures were identified, giving an overall failure rate of 27.6%. Prosthesis survival at five years was 75.5%, and at ten years was 59%. At last follow-up, mean knee flexion was 89.8° (SD 36°) with a mean extensor lag of 18.1° (SD 24°). In univariate analysis, factors associated with better survival of the prosthesis were a malignant or metastatic cancer diagnosis (versus benign), with a five- and ten-year survival of 78.9% and 65.7% versus 37.5% (p = 0.045), while in-hospital length of stay longer than nine days was also associated with better prognosis with five- and ten-year survival rates at 84% and 84% versus 60% and 16% (p < 0.001). In multivariate analysis, only in-hospital length of stay was associated with longer survival (hazard ratio (HR) 0.23, 95% confidence interval (CI) 0.08 to 0.66).

Conclusion

We have shown that proximal tibial arthroplasty with endoprosthesis is a safe and reliable method for reconstruction in patients treated for orthopaedic oncological conditions. Either modular or custom implants in this series performed well.

Cite this article: Bone Jt Open 2022;3(9):733–740.

The functional outcome after tumor resection and endoprosthesis around the knee: a systematic review

The evidence for the functional outcome of endo- prosthetic replacement (EPR) after tumour resection has been from few cohort studies. A scoping search revealed no systematic review on patient reported outcome measures after EPR around the knee. The purpose of this study was to evaluate the functional outcome of distal femoral and proximal tibial EPR after tumour resection. A systematic review was conducted using the PRISMA guidelines. The search identified 2560 articles from MEDLINE, EMBASE, CINAHL, and Web of Science. 36 studies satisfying the selection criteria were included for data synthesis. Pooled analysis was performed for homogenous studies. Narrative synthesis was performed for all the studies due to heterogeneity in methodological and statistical analysis. Amongst the overall patient population of 2930, mean ages ranged from 18-66 years and the mean follow up periods in the studies ranged from 12 - 180 months. The weighted mean functional outcome was similar for patients who had DFEPR and PTEPR. The functional outcome scores of Rotating Hinge Knee implants (RHK) were significantly greater than that for Fixed Hinge Knee implants (FHK). The weighted mean functional outcome scores were higher after cemented fixation and after primary EPR procedures. The current evidence suggests that functional out- come after EPR in the knee is good, and RHK implants are better than FHK implants. Functional outcome after primary EPR was significantly better than following revision EPR, and this underscores the importance of minimising complications at the primary surgery.

Implant Survival, Clinical Outcome and Complications of Megaprosthetic Reconstructions Following Sarcoma Resection

Simple Summary

Malignant bone and soft tissue tumors are usually surgically removed with an envelope of healthy tissue as a barrier. If located in the long bones of the upper and lower extremity, this approach leads to a large bone defect commonly affecting a joint. One way to rebuild the bone defect and the neighboring joint is the use of a megaprosthesis that is anchored in the remaining bone comparable to a conventional joint replacement. In general this approach is popular as it provides early stability and allows the affected patient to begin rehabilitation early on. However, complications leading to long-term unplanned reoperation are common. This article provides an overview of current implant survival, types of complication and long-term outcomes of megaprostheses used following tumor resection.

Abstract

Megaprosthetic reconstruction of segmental bone defects following sarcoma resection is a frequently chosen surgical approach in orthopedic oncology. While the use of megaprostheses has gained popularity over the last decades and such implants are increasingly used for metastatic reconstructions and in non-tumor cases, there still is a high risk of long-term complications leading to revision surgery. This article investigates current implant survivorship, frequency and types of complications as well as functional outcomes of upper and lower limb megaprosthetic reconstructions.

Mid-term implant survival, functional and radiological results and mechanical complications of mega-prosthetic reconstruction around the knee with the PENTA® system

AIM

Mega-prosthetic reconstruction is the most common treatment method for massive osteoarticular defects caused by tumor resection around the knee. The new implant is a highly modular rotational-hinged megaprosthesis system with a distinct pentagonal stem geometry and variable implantation options. The aim of this study is to present the mid-term implant survival characteristics, functional and radiological results and mechanical complication profile of the new megaprosthesis.

METHODS

One hundred and one mega-prosthetic knee reconstruction procedures in 90 patients (M/F: 51/39) utilizing the new implant system were retrospectively analyzed. In 68 patients, the megaprosthesis was used for primary reconstruction following tumor resection while it was used for revision of other implants in 22. The mean age was 28.5 (7-66) years and the mean follow-up was 59.2 (24-124) months. The most common primary pathology was osteosarcoma with 63-70% patients, the most common anatomical site of involvement was the distal femur with 56-62% patients.

RESULTS

Henderson Type 2 failure (aseptic loosening) was seen in only 2-2.2% patients while Type 3 (structural failure) was seen in 29-32.2% Although the 5-year anchorage survival rate was 94.3%, overall mechanical implant survival was 76.1% at 5 years due to a relatively high failure rate in the first-generation hinge mechanism of the implant. The 5-year hinge survival rate demonstrated a significant improvement rate from 61.7% to 87.2% between the first and second generations of the implant (p = 0.027). The mean MSTS score was 24 out of 30 (14-29). The mean cumulative ISOLS radiographic score for index megaprosthesis operations was 19.7 (12-24), which corresponded to excellent outcome.

CONCLUSION

The new megaprosthesis system is a reliable choice for the reconstruction of tumor-related massive osteoarticular defects around the knee. Although long-term follow-up is necessary for a definitive evaluation of the implant's survival characteristics, midterm follow-up yields exceptional anchorage properties related to pentagonal stem geometry with very good functional outcomes.

The risk factors for mechanical complication in endoprosthetic reconstruction of knee osteosarcoma

BACKGROUND

The increased limb survival rates and higher functional demands have also increased the mechanical complication rates of megaprostheses. This study aimed to analyse possible risk factors which can predispose patients to mechanical complications.

METHODS

Patients with knee osteosarcoma referred to our clinic from 1992 to 2014 were investigated retrospectively. The patients who underwent surgical resection and endoprosthetic reconstruction with at least 5 years of follow up were analysed. The revision of the megaprosthesis due to a mechanical complication was accepted as an endpoint. The possible risk factors, including cement usage, implant material, joint mechanism, neoadjuvant radiotherapy, and anatomical localization of the lesion, were analysed for any association with mechanical complication rates.

RESULTS

A total of 118 patients were included for final analysis. The average age was 24.5 years (standard deviation ±10.1, range: 15-64). Mechanical complication rate was 22% which included 19 aseptic loosenings and seven implant failures. The average time to mechanical complication was 32.5 months. Overall, 5-year implant survival was 78%. Multiple regression analysis revealed that cement usage is an independent risk factor for mechanical complication (P = 0.007). Although the 5-year implant survival was higher in rotating hinge and titanium implants compared with fixed hinge and cobalt chrome, the multiple regression model did not yield a correlation with mechanical complication rates.

CONCLUSION

Cemented implants showed significantly higher mechanical complication rates compared with cementless ones in this series of knee osteosarcoma patients who underwent megaprosthetic reconstruction. Hinge mechanism and implant material did not have a significant effect on mechanical complication rates.

Reconstruction of the extensor mechanism augmented with reverse transferred iliotibial band after proximal tibia tumor resection and mega-prosthetic replacement

BACKGROUND

The optimal procedure for functional reconstruction of the extensor mechanism after proximal tibia mega-prosthetic replacement remains unclear.

METHODS

Since 2006, 14 consecutive patients with aggressive bone tumors in the proximal tibia who underwent mega-prosthetic replacement were prospectively treated with reconstruction of the extensor mechanism using an ipsilateral iliotibial band. The surgical procedure consisted of wrapping the reversed iliotibial band around the tibia component, firmly suturing it to the remaining patellar tendon and tibialis anterior fascia, and covering it with a muscle flap. At the last follow up, the function was assessed based on extensor lag, active flexion of the knee, and Musculoskeletal Tumor Society score. Patellar height was measured with the Insall-Salvati ratio (ISR) preoperatively, postoperatively, and at the last follow up.

RESULTS

At the last follow up, the extensor lag and active flexion in 14 patients averaged 2.5° and 86°, respectively. Musculoskeletal Tumor Society score could be obtained in nine surviving patients at the last follow up and was a mean of 20.7 points. The mean ISR preoperatively, postoperatively, and at the last follow up was 1.04, 0.75, and 0.89, respectively. The extensor lag was not associated with the ISR value at any points, while reduced active flexion significantly correlated with a low ISR at the last follow up (P = 0.015). Four patients underwent additional surgeries due to postoperative infection, but none required eventual revision or amputation.

CONCLUSION

The extensor mechanism reconstruction with the reverse transferred iliotibial band for mega-prosthetic replacement after proximal tibia resection yielded reliable outcomes with functional benefit to stabilize active knee extension.

Differences in Kinematic and Kinetic Patterns According to the Bone Tumor Location after Endoprosthetic Knee Replacement Following Bone Tumor Resection: A Comparative Gait Analysis between Distal Femur and Proximal Tibia

Modular endoprostheses are frequently used to reconstruct skeletal and knee defects from bone tumor resection and preserve joint function in patients with bone tumors around the knee. Depending on the tumor location, the muscles and extent of the tumor can vary, which can affect gait function. This study aimed to analyze kinetic and kinematic characteristics according to tumor location in patients with endoprosthetic knee replacements after bone tumor resection. Gait analyses were performed in 16 patients who underwent knee endoprosthesis due to tumors around the knee. We divided the patients into distal femur (n = 7) and proximal tibia (n = 9) groups and conducted between-group comparisons and comparisons with healthy participants. Compared with the control group, the distal femur group showed a tendency for knee extension, and the proximal tibia group showed increased maximal dorsiflexion during stance. The proximal tibia group maintained a flexed hip during the entire gait cycle, compared with the distal femur group. In summary, our results suggest a difference in gait between the distal femur and proximal tibia groups. Patients who have undergone knee prosthesis after knee tumor resection may require different rehabilitation strategies according to the tumor location.

Individual Revision Knee Arthroplasty Is a Safe Limb Salvage Procedure

Introduction: Revision total knee arthroplasty after multiple pre-surgeries is challenging. Due to severe bone defects, standard implants for metaphyseal and diaphyseal anchoring may no longer be suitable. The primary aim of this case series is to evaluate the early complication rate for individual knee implants with custom-made cones and stems after two-stage revision with severe bone defects. Methods: Ten patients who were treated with custom-made 3D-printed knee revision implants were included. Inclusion criteria were a two-stage revision due to late-onset or chronic periprosthetic joint infection as well as aseptic loosening. All severe bone defects were AORI type III. All procedure-related complications were evaluated. Postoperative range of motion after one year was measured. The time between the two surgeries was evaluated. Results: The mean follow-up was 21 months (range: 12–40). The mean time between the two-stage surgeries was 71.6 days. No fractures were observed intra- and postoperatively. Two patients were revised without changing metal components due to persistent hematoma (three weeks post-surgery) and persistent PJI (three months post-surgery). The mean passive postoperative range of motion was 92° (range: 80–110°). Conclusions: Individual custom-made implants for rTKA provide a safe procedure for patients with huge bone defects after several pre-surgeries. If standard knee systems with standard cones or sleeves are not suitable anymore, custom-made treatment offers the patient the last option for limb preservation. However, this is associated with increased costs.

Osteointegration of hydroxyapatite-coated collars in cemented massive endoprostheses following revision surgery

Aims

Hydroxyapatite (HA)-coated collars have been shown to reduce aseptic loosening of massive endoprostheses following primary surgery. Limited information exists about their effectiveness in revision surgery. The aim of this study was to radiologically assess osteointegration to HA-coated collars of cemented massive endoprostheses following revision surgery.

Methods

Retrospective review of osseointegration frequency, pattern, and timing to a specific HA-coated collar on massive endoprostheses used in revision surgery at our tertiary referral centre between 2010 to 2017 was undertaken. Osseointegration was radiologically classified on cases with a minimum follow-up of six months.

Results

In all, 39 patients underwent radiological review at mean 43.5 months; 22/39 (56.4%) showed no osseointegration to the collar. Revision endoprostheses for aseptic loosening were less likely to show osseointegration compared with other indications for revision. Oncological cases with previous or current infection were more likely to show osseointegration to ≥ 1 collar side than those without evidence of prior infection.

Conclusion

This seven-year review identified osseointegration of HA-coated collars after revision surgery is less likely (43.6%, 17/39) than after primary surgery. Young patients who undergo revision surgery following initial oncological indication may benefit the most from this collar design. Use in revision oncological cases with a history of infection may be beneficial. HA-coated collars showed limited benefit for patients undergoing revision for failed arthroplasty with history of infection.

Cite this article: Bone Jt Open 2021;2(6):371–379.

Surgical treatment of skeletal metastases in proximal tibia: a multicenter case series of 74 patients

Background and purpose - The proximal tibia is a rare site for metastatic bone disease and is a challenging anatomical site to manage due to the proximity to the knee joint and poor soft tissue envelope. We investigated implant survival and complications of different surgical strategies in the treatment of proximal tibia pathological fractures.Patients and methods - The study comprised a 4 medical center, retrospective analysis of 74 patients surgically treated for metastases of the proximal tibia. Patient records were reviewed to identify outcome, incidence, and type of complications as well as contributing factors.Results - Reconstruction techniques comprised cement-augmented osteosynthesis (n = 33), tumor prosthesis (n = 31), and total knee arthroplasty with long cemented stems (n = 10). Overall implant survival was 88% at 6 months and 1 year, and 67% at 3 years. After stratification by technique, the implant survival was 82% and 71% at 1 and 3 years with tumor prosthesis, 100% at 1 and 3 years with total knee arthroplasty, and 91% at 1 year and 47% at 3 years with osteosynthesis. Preoperative radiotherapy decreased implant survival. Complications were observed in 19/74 patients. Treatment complications led to amputation in 5 patients.Interpretation - In this study, the best results were seen with both types of prothesis reconstructions, with good implant survival, when compared with treatment with osteosynthesis. However, patients treated with tumor prosthesis showed an increased incidence of postoperative infection, which resulted in poor implant survival. Osteosynthesis with cement is a good alternative for patients with short expected survival whereas endoprosthetic replacement achieved good medium-term results.

Balance and constraint in revision TKR: A classification for instability management

Instability is an increasingly common cause and symptom of failure of Total Knee Arthroplasty (TKA). Patients seek 'Functional Stability', which is the sum of both a balanced joint and, if necessary, mechanical constraint. The objective of this paper is to classify the different types of TKA instability and their causes. Based on this classification, the authors give methodical recommendations for instability management.

Instability classification

Instability in revision TKA can be classified into 3 types based on the management of bone loss and ligamentous deficiency which directs the level of constraint required to achieve functional stability.

Type 1

Bone deficiency: Revision with restoration of joint line and rebuilding the bony anatomy results in a balanced joint. No increased constraint is needed.

Type 2

Ligament and soft tissue deficiency: Requires increased constraint to overcome instability.

Type 3

Composite (Total) deficiency: (combined Type 1 and 2).The multiple causes of instability are outlined for each Instability type along with an algorithm for restoring the joint line and adding titrated constraint to restore functional stability.

Osteoarticular allograft reconstruction after distal radius tumor resection: Reoperation and patient reported outcomes

BACKGROUND

The aims of this study are to evaluate the rate of wrist joint preservation, allograft retention, factors associated with reoperation and to report the patient reported outcomes after osteoarticular allograft reconstruction of the distal radius.

METHODS

Retrospective chart review identified 33 patients who underwent distal radius resection followed by osteoarticular allograft reconstruction, including 27 giant cell tumors and 6 primary malignancies. Ten patients with a preserved wrist joint completed the QuickDASH, PROMIS-CA physical function, and Toronto extremity salvage score (TESS) at a median of 13 years postoperatively.

RESULTS

The allograft retention rate was 89%, and an allograft fracture predisposed to conversion to wrist arthrodesis. The reoperation rate was 55% and 36% underwent wrist arthrodesis at a median of 4.2 years following index surgery. The use of locking plate fixation was associated with lower reoperation and allograft fracture rates. Patients reported a median QuickDASH of 10.2 (range: 0-52.3), a mean PROMIS physical function of 57.8 (range: 38.9-64.5) and the median TESS was 95.5 (range: 67.0-98.4).

CONCLUSION

Osteoarticular allograft reconstruction results in acceptable long-term patient reported outcomes, despite a high revision rate. Allograft fixation with locking plates seems to reduce the number of reoperations and allograft fractures, along with reduction in wrist arthrodesis rates.

Options and limitations of implant constraint

With an ever-increasing number of revisions, the surgeons will be faced with the dilemma of choosing the right implant for the revision knee. The soft tissue viability governs the choice of an implant at the time of revision. The selection ranges from the cruciate-retaining to the rotating/fixed hinge implants. The surgeon needs to plan preoperatively, but usually, the final decisions are made intraoperative. As determining the amount of constraint necessary can be challenging, we have tried to lay down a few pointers, which would help to make that choice. The posterior stabilized implants can manage most revision knees; in certain situations where they cannot accommodate the flexion-extension gap imbalance, a varus-valgus constrained implant should be used. The rotating hinge implants are used for severe instabilities or loss of soft tissue or bone around the knee. The use of a higher constraint implant has its consequences like reduced life span and reduced function. Thus it is crucial to use the least amount of constraint as necessary - however, as much as required.

Is a single dose of preoperative antibiotic therapy effective for patients treated with megaendoprosthesis after metastatic bone tumour resection?

Purpose The timing and number of doses of antibiotics required for megaendoprosthetic replacement (MPR) in metastatic bone disease (MBD) is a matter of debate. The aim of our study is to present the results of a prospective cohort of MPR for MBD receiving a single dose of antibiotic at induction of anaesthesia.

METHODS

All patients who underwent primary MPR in MBD were included in this prospective study. All penicillin-sensitive patients received one dose of cefuroxime 1.5gm intravenous at induction. In penicillin-allergic patients, teicoplanin 1.2gm and ciprofloxacin 500 mg intravenous was administered. The patients were followed up in the wound clinic and the specialist MBD clinic at 2 weeks, 3 months, 6 months and then annually. Data collected included demographics, primary tumours, surgical procedures, complications and duration of follow-up. All calculations were performed using SPSS^® 25(IBM, USA). A p value ≤ 0.05 was considered to be significant.

RESULTS

There were 51 patients with a mean age of 65.4 years. Procedures included proximal femoral replacement (35), distal femoral replacement (7), proximal humeral replacement (4), distal humeral replacement (3) and total femoral replacement (2). Thirty-seven patients received cefuroxime, and fourteen patients received teicoplanin and ciprofloxacin at induction of anaesthesia. The deep infection rate was 1.9%. Thirty-seven patients died with a median survival of 10 months (1 to 51 months). Mean follow-up was 18.9 months (1 to 70 months).

CONCLUSION

Single dose of preoperative antibiotics at anaesthetic induction seems to be safe and effective for preoperative prophylaxis in orthopaedic oncology.

What Is the 10-year Survivorship of Cemented Distal Femoral Endoprostheses for Tumor Reconstructions and What Radiographic Features Are Associated with Survival?

BACKGROUND

Aseptic loosening is one of the most common causes of revision of distal femoral endoprostheses and is considered a mid- to long-term complication. There are not many reports of 10-year survivorship free from aseptic loosening and all-cause survivorship in cemented stems. To our knowledge, there are no reports on radiographic features that are associated with aseptic loosening of these implants.

QUESTIONS/PURPOSES

(1) What is the 5- and 10-year survivorship free from aseptic loosening in patients undergoing reconstruction with a cemented distal femoral endoprosthesis after a tumor resection? (2) What is the all-cause 5- and 10-year survivorship at in these patients? (3) What radiographic features are associated with aseptic loosening at long-term follow-up?

METHODS

We performed a multicenter retrospective study reviewing aseptic loosening in cemented prostheses to determine radiographic features associated with long-term implant survivorship. Patients who underwent a cemented distal femoral reconstruction with a modular endoprosthesis after resection of a musculoskeletal tumor between 1997 and 2017 were reviewed. A total of 246 patients were identified from five institutions and met initial inclusion criteria. Of those, 21% (51) were lost to follow-up before 2 years, leaving 195 patients available for us to evaluate and analyze the survivorship and radiologic features associated with long-term implant survival. The mean (range) follow-up was 78 months (22 to 257). At the time of this analysis, 69% (135 of 195) of the patients were alive. Osteosarcoma was the most common diagnosis in 43% of patients (83 of 195), followed by metastatic carcinoma 13% (25 of 195). Fifty-six percent (110 of 195) of patients received chemotherapy; 15% (30 of 195) had radiation therapy. Aseptic loosening was diagnosed radiographically and was defined as a circumferential radiolucent line on all views, or subsidence around the stem in the absence of infection. We present 5- and 10-year Kaplan-Meier survivorship free from aseptic loosening, 5- and 10-year all-cause survivorship, and a qualitative assessment of radiographic features potentially associated with aseptic loosening (including the junctional radiolucent area, and cortical expansion remodeling). The junctional radiolucent area was defined as a radiolucent area of the bone starting at the bone-endoprosthesis junction to the tip of the femoral stem, and cortical expansion remodeling was defined as an increased cortical thickness at the stem tip. Although we wished to statistically analyze radiographic factors potentially associated with aseptic loosening, we did not have enough clinical material to do so (only nine patients developed loosening). Instead, we will report a few preliminary qualitative observations, which necessarily are preliminary, and which will need to be confirmed or refuted by future studies. We urge caution in interpreting these findings because of the very small numbers involved.

RESULTS

Kaplan-Meier survivorship free from aseptic loosening of the femoral component at 5 and 10 years were 95% (95% CI 89 to 98) and 93% (95% CI 86 to 97), respectively. Kaplan-Meier survivorship free from revision for any cause at 5 and 10 years were 74% (95% CI 65 to 79) and 64% (95% CI 49 to 70), respectively. Although the numbers were too small to analyze statistically, all patients with aseptic loosening had a junctional radiolucent area more than 20% of the total length of the stem without cortical expansion remodeling at the stem tip. No aseptic loosening was observed if there was cortical ex remodeling, a junctional radiolucent area less than 20%, or curved stems that were 13 mm or greater in diameter. The numbers of patients with aseptic loosening in this series were too small to analyze statistically.

CONCLUSIONS

Cemented distal femoral endoprostheses have a relatively low rate of aseptic loosening and acceptable projected first-decade survivorship. The presence of a radiolucent area more than 20% without cortical expansion remodeling at the stem tip may lead to aseptic loosening in patients with these implants. Close radiographic surveillance and revision surgery may be considered for progressive lucencies and clinical symptoms of pain. If revision is contemplated, we recommend using larger diameter curved cemented stems. These are preliminary and provisional observations based on a low number of patients with aseptic loosening; future studies with greater numbers of patients are needed to validate or refute these findings.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Predictive Value of the Nomogram Model in Patients With Megaprosthetic Failure Around the Knee: A Retrospective Analysis

BACKGROUND

Megaprosthetic replacement is one of the main methods for reconstructing mega bone defects after tumor resection. However, the incidences of complication associated with tumor prostheses were 5-10 times higher than that of conventional total knee arthroplasty. The objective of this study is to establish and validate a nomogram model which can assist doctors and patients in predicting the prosthetic survival rates.

METHODS

Data on cancer patients treated with tumor prosthesis replacements at our institution from November 2001 to November 2017 were collected. The potential risk factors which were well-studied and shown to be associated with megaprosthetic failure were analyzed. A nomogram model was established using independent risk factors screened out by multivariate regression analysis. The concordance index and calibration curve were selected for internal validation of the predictive accuracy of nomogram.

RESULTS

The 3-, 5-, 10-, and 15-year prosthetic survival rates were 92.8%, 88.6%, 74.1%, and 48.3%, respectively. The prosthetic motion mode, body mass index, type of reconstruction, type of prosthesis, and length of bone resection were independent risk factors for tumor prosthetic failure. A nomogram model was established using these significant predictors, with a concordance index of 0.77 and a favorable consistency between predicted and actual prosthetic failure rate according to the internal validation, indicating that the nomogram model had acceptable predictive accuracy.

CONCLUSION

The prediction model identifies high-risk patients for whom attached preventive measures are required. Future studies regarding reduction in incidence of prosthetic failure should attach importance to these high-risk patients.

Salvage of Distal Femoral Replacement Loosening with Massive Osteolysis Using Impaction Grafting: A Report of 2 Cases

CASE

Salvage of 2 cases of distal femoral replacement loosening with massive osteolysis using impaction grafting are presented with 9- and 11-year follow-ups.

CONCLUSION

Surgeons should keep impaction grafting in their armamentarium for cases of failed DFR with severe osteolysis. Doing so may allow for preservation of the native hip and deferment of more radical procedures (i.e. total femur replacement) that have high rates of complication and poor survivorship.

The effects of length of femoral stem on aseptic loosening following cemented distal femoral endoprosthetic replacement in tumour surgery

PURPOSE

Aseptic loosening is a common prosthetic failure mode. The purpose of this study was to identify dose-response relationship between length of femoral stem and aseptic loosening.

METHODS

We collected data of patients who underwent distal femoral prosthetic replacements at our institution from 2001 to 2017. Cox regression and two-piecewise regression model were used to analyze the associations between stem length and aseptic loosening.

RESULTS

Significant association of length of femoral stem with aseptic loosening was observed in multivariate model and a non-linear relationship could be found from the smoothed curve. In two-piecewise model, an inflection point was calculated to be 143 mm. On the left of the inflection point, every 1 mm increase in the length of stem indicated that the risk of aseptic loosening could be reduced by 6%.

CONCLUSION

There was a significant non-linear relationship between the length of femoral stem and aseptic loosening, and the inflection point was 143 mm.

How is the outcome of the Limb Preservation System™ for reconstruction of hip and knee?

BACKGROUND

Despite tremendous advantages in the development and application of megaprostheses in tumour and revision surgery, complications are still not infrequently observed. Only two studies investigating the outcome of the LPS™ system in the proximal femur and distal femur/proximal tibia have been published thus far. Herein, mid-term implant survival rates one of the largest cohort of patients treated with the LPS™-system are presented aiming tp answer: 1) How is the outcome of the LPS™ system in the proximal femur and distal femur/proximal tibia? 2) Which factors are associated with altered implant survival? 3) What is the cumulative risk of complications according to Henderson?

HYPOTHESIS

The LPS™-system is associated with high complication rates that depend on implant site, with infections being most common.

PATIENTS AND METHODS

Fifty-seven patients who received the LPS™-system at the proximal femur (n=31), distal femur (n=21) and proximal tibia (n=5) between 2004 and 2010 for oncological (n=40) or non-oncological (n=17) causes, were retrospectively included. Median follow-up was 5.0 years (range, 0-12.4 years). Complications were classified according to Henderson into instability/soft tissue failure (type 1), aseptic loosening (type 2), structural failure (type 3), periprosthetic infection (type 4), tumour progression (type 5). Competing-risk-analyses were applied to estimate implant survival with death as the competing event.

RESULTS

Twenty-six patients (45.6%) developed a complication, of whom 9 (29.0%) had a proximal femoral and 17 (65.4%) a distal femoral/proximal tibial implant. Type 4 complications were most common (n=11), followed by type 3 (n=6, including 2 yoke-fractures), type 1 and 2 (n=4 each), and type 5 (n=1). The only factor associated with the development of complications in the multivariate model was a distal femoral/proximal tibial implant (hazard-ratio: 7.418, 95% confidence-interval: 2.193-26.096, p=0.001), irrespective of reason for reconstruction and use of muscular flaps. The cumulative-incidence of failure including all complications was 34.3%, 40.7% and 67.1% at 3, 5 and 10 years, respectively.

DISCUSSION

The LPS™-system may be used for proximal femoral reconstructions both in the oncological and non-oncological setting. Rates of complications are higher in our cohort than reported in literature for other, comparable, megaprosthesis systems. Especially in the distal femur/proximal tibia, complication rates were high, partially attributable to the former implant design leading to fractures of the yoke-mechanism. As the implant has been remodelled after these issues became evident, there is no objection to use this megaprosthesis system today.

LEVEL OF EVIDENCE

IV, Observational Study.

[Risk factors and management strategies for early and late infections following reconstruction with special tumour endoprostheses]

BACKGROUND

Periprosthetic joint infection (PJI) of megaprostheses occur in about 10% of all cases. The criteria for PJI are defined by the "Musculoskleletal Infection Society" (MSIS) and apply to both primary arthroplasty and megaprostheses.

MANAGEMENT

The management strategies of PJI in megaprostheses are dependent on the duration of infection and the maturity of the bacterial biofilm. Implant retention with an exchange of the mobile components is only possible in the presence of an immature biofilm. In the presence of a mature biofilm, a one- or two-stage exchange must be performed. A complete exchange of all endoprosthetic components should be performed, if possible, since a partial retention of isolated components results in inferior treatment success rates.

RESULTS

The highest success rates are achievable with two-stage exchanges. Multiple risk factors such as skin necrosis, postoperative haematoma, prolonged wound secretion and operative times ≥ 2.5 h are risk factors for the development of PJI in megaprostheses. Knowledge regarding these risk factors allows for an identification of high-risk patients and early management of PJI.

Extendable Endoprostheses in Skeletally Immature Patients: A Study of 124 Children Surviving More Than 10 Years After Resection of Bone Sarcomas

BACKGROUND

Extendable endoprostheses are used to reconstruct segmental defects following resection of bone sarcomas in skeletally immature patients. However, there remains a paucity of studies with regard to long-term outcomes.

METHODS

We retrospectively reviewed 124 skeletally immature children who underwent an extendable endoprosthetic replacement and survived more than 10 years after the surgical procedures. Anatomical sites included the distal part of the femur (n = 66), the proximal part of the femur (n = 13), the proximal part of the tibia (n = 29), and the proximal part of the humerus (n = 16). Complications and implant survival were classified according to the modified Henderson criteria.

RESULTS

The mean follow-up was 24 years (range, 10 to 36 years). The mean age at the time of the extendable endoprosthetic replacement was 9 years (range, 2 to 16 years). All patients had reached skeletal maturity at the last follow-up. The 10-year endoprosthetic failure-free survival rate was 28%. A total of 243 complications occurred in 90% of patients; these complications were most frequently related to soft-tissue problems (27% of complications). The incidence of and cumulative survival with respect to each failure mode varied between anatomical sites. Soft-tissue failures occurred most frequently in the proximal part of the femur (77%; p = 0.003), and the distal part of the femur was the most frequent site of aseptic loosening (52%; p = 0.014) and structural failure (55%; p = 0.001). Excluding lengthening procedures, 105 patients (85%) underwent an additional surgical procedure, with a mean of 2.7 surgical procedures per patient (range, 0 to 7 surgical procedures per patient). The mean limb-length discrepancy at the final follow-up was 1 cm (range, 0 to 9 cm). Limb salvage was achieved in 113 patients (91%). The mean Musculoskeletal Tumor Society functional score (the percentage of a total score of 30 points) was 82% (range, 40% to 100%) in 115 patients with available data at the last follow-up.

CONCLUSIONS

Extendable endoprostheses are associated with a high complication rate and a need for additional surgical procedures over time. Despite this, successful limb salvage with reasonable function and small limb-length discrepancy is achievable in the long term. Our study provides benchmark data for individual anatomical sites for further improvements of outcomes.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Establishment and validation of a nomogram model for aseptic loosening after tumor prosthetic replacement around the knee: a retrospective analysis

Background

Aseptic loosening has become the main cause of prosthetic failure in medium- to long-term follow-up. The objective of this study was to establish and validate a nomogram model for aseptic loosening after tumor prosthetic replacement around knee.

Methods

We collected data on patients who underwent tumor prosthetic replacements. The following risk factors were analyzed: tumor site, stem length, resection length, prosthetic motion mode, sex, age, extra-cortical grafting, custom or modular, stem diameter, stem material, tumor type, activity intensity, and BMI. We used univariate and multivariate Cox regression for analysis. Finally, the significant risk factors were used to establish the nomogram model.

Results

The stem length, resection length, tumor site, and prosthetic motion mode showed a tendency to be related to aseptic loosening, according to the univariate analysis. Multivariate analysis showed that the tumor site, stem length, and prosthetic motion mode were independent risk factors. The internal validation indicated that the nomogram model had acceptable predictive accuracy.

Conclusions

A nomogram model was developed for predicting the prosthetic survival rate without aseptic loosening. Patients with distal femoral tumors and those who are applied with fixed hinge and short-stem prostheses are more likely to be exposed to aseptic loosening.

Rotating-hinge knee prosthesis as a viable option in primary surgery: Literature review & meta-analysis

BACKGROUND

Rotating-hinge knee replacements are usually reserved for revision surgeries, when the extent of soft tissue loss makes a constrained implant more suitable. They remain an uncommon choice in primary surgery when the soft tissue loss is not as extensive.

METHODS

We completed a systematic review and meta-analysis to assess patients who underwent a Total Knee Replacement (TKR) with the rotating-hinge prosthesis in the primary setting. We searched PubMed and Embase for articles published in the ten years prior June 2017: Prosthesis survival rates, causes of failure, and clinical/functional scores were the primary outcomes. Twenty-one articles met the inclusion criteria for meta-analysis. Articles were grouped into (1) non-tumour (n=11) and (2) tumour indications (n=10). Survival data was summarized in forest plots, generated using Stata.

RESULTS

We found that for certain indications the prosthesis has impressive survival rates and functional outcomes. Short-term (1-5 year) prosthesis survival in non-tumour cases was 92% (95% CI, 87-98%) and 77% (95% CI, 68-87%) in tumour cases. Mid-term (6-10 year) survival was 82% (95% CI, 74-89%) and 69% (95% CI, 57-81%) in non-tumour and tumour studies respectively. In analysis of clinical scores, patients showed a significant improvement in their pain score. Infection was the most commonly cited cause of prosthesis failure in both non-tumour and tumour studies, attributing to 31.5% and 37.6% of failures respectively. Aseptic loosening, dislocation and fracture were also commonly cited complications.

CONCLUSION

We concluded that the rotating-hinge knee prosthesis is a viable option in primary surgery when there is extensive soft tissue destruction surrounding the joint.

LEVEL OF EVIDENCE

I.

A retrospective study of antibacterial iodine-coated implants for postoperative infection

Postoperative infection is one of the most serious complications in orthopedic surgery. We have developed and use iodine-coated implants to prevent and treat postoperative infection in compromised hosts. This study evaluated outcomes using iodine-coated implants for postoperative infections.We treated 72 postoperative infected patients using iodine-coated implants. Of these, 38 were males and 34 were females, with a mean age of 59.3 years. The mean follow-up period was 5.6 years. The patients included 23 with an infection following total knee arthroplasty, 20 following total hip arthroplasty, 11 following osteosynthesis, 11 following spine surgery, 6 following tumor excision, and 1 following osteotomy. Of these, 37 underwent single-stage surgery and 35 underwent staged revision surgery. We performed staged surgery in any case with active infection. The survival of iodine-coated implants was determined using Kaplan-Meier analysis. White blood cell (WBC) and C-reactive protein (CRP) levels were measured pre- and postoperatively. To evaluate the systemic effects of iodine, serum thyroid hormone levels were examined.Five patients underwent re-revision surgery. In 3 patients, periprosthetic infection recurred at an average of 18 months after surgery. The reinfection rate was 4.2%. These patients recovered following reimplantation of iodine-coated prostheses. No patients required amputation. The survival rate of iodine-coated implants was 91%. There were no signs of infection at the latest follow-up. The median WBC level was nearly in the normal range, and CRP levels returned to normal within 4 weeks after surgery. No abnormalities of thyroid gland function were detected.Iodine-coated titanium implants can be very effective in the treatment of postoperative infections. An iodine coating can be safely applied to infected regions.

Physeal-preserving endoprosthetic replacement with short segment fixation in children with bone sarcomas

AIMS

The aim of this study was to report the results of custom-made endoprostheses with extracortical plates plus or minus a short, intramedullary stem aimed at preserving the physis after resection of bone sarcomas in children.

PATIENTS AND METHODS

Between 2007 and 2017, 18 children aged less than 16 years old who underwent resection of bone sarcomas, leaving ≤ 5 cm of bone from the physis, and reconstruction with a custom-made endoprosthesis were reviewed. Median follow-up was 67 months (interquartile range 45 to 91). The tumours were located in the femur in 11 patients, proximal humerus in six, and proximal tibia in one.

RESULTS

The five-year overall survival rate was 78%. No patient developed local recurrence. The five-year implant survival rate was 79%. In all, 11 patients (61%) developed a complication. Seven patients (39%) required further surgery to treat the complications. Implant failures occurred in three patients (17%) including one patient with aseptic loosening and two patients with implant or periprosthetic fracture. The preserved physis continued to grow at mean 3.3 cm (0 to 14). The mean Musculoskeletal Society score was 88% (67% to 97%).

CONCLUSION

Custom-made endoprostheses that aim to preserve the physis are a safe and effective option for preserving physeal growth, limb length, and joint function with an acceptable rate of complications. Cite this article: Bone Joint J 2019;101-B:1144-1150.

Proximal Tibial Reconstruction After Tumor Resection: A Systematic Review of the Literature

BACKGROUND

The proximal part of the tibia is a common location for primary bone tumors, and many options for reconstruction exist following resection. This anatomic location has a notoriously high complication rate, and each available reconstruction method is associated with unique risks and benefits. The most commonly utilized implants are metallic endoprostheses, osteoarticular allografts, and allograft-prosthesis composites. There is a current lack of data comparing the outcomes of these reconstructive techniques in the literature.

METHODS

A systematic review of peer-reviewed observational studies evaluating outcomes after proximal tibial reconstruction was conducted, including both aggregate and pooled data sets and utilizing a Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) review for quality assessment. Henderson complications, amputation rates, implant survival, and functional outcomes were evaluated.

RESULTS

A total of 1,643 patients were identified from 29 studies, including 1,402 patients who underwent reconstruction with metallic endoprostheses, 183 patients who underwent reconstruction with osteoarticular allografts, and 58 patients who underwent with reconstruction with allograft-prosthesis composites. The mean follow-up times were 83.5 months (range, 37.3 to 176 months) for the metallic endoprosthesis group, 109.4 months (range, 49 to 234 months) for the osteoarticular allograft group, and 88.8 months (range, 49 to 128 months) for the allograft-prosthesis composite reconstruction group. The mean patient age per study ranged from 13.5 to 50 years. Patients with metallic endoprostheses had the lowest rates of Henderson Type-1 complications (5.1%; p < 0.001), Type-3 complications (10.3%; p < 0.001), and Type-5 complications (5.8%; p < 0.001), whereas, on aggregate data analysis, patients with an osteoarticular allograft had the lowest rates of Type-2 complications (2.1%; p < 0.001) and patients with an allograft-prosthesis composite had the lowest rates of Type-4 complications (10.2%; p < 0.001). The Musculoskeletal Tumor Society (MSTS) scores were highest in patients with an osteoarticular allograft (26.8 points; p < 0.001). Pooled data analysis showed that patients with a metallic endoprosthesis had the lowest rates of sustaining any Henderson complication (23.1%; p = 0.009) and the highest implant survival rates (92.3%), and patients with an osteoarticular allograft had the lowest implant survival rates at 10 years (60.5%; p = 0.014).

CONCLUSIONS

Osteoarticular allograft appears to lead to higher rates of Henderson complications and amputation rates when compared with metallic endoprostheses. However, functional outcomes may be higher in patients with osteoarticular allograft. Further work is needed using higher-powered randomized controlled trials to definitively determine the superiority of one reconstructive option over another. In the absence of such high-powered evidence, we encourage individual surgeons to choose reconstructive options based on personal experience and expertise.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Rotating-Hinge Revision Total Knee Arthroplasty for Treatment of Severe Arthrofibrosis

BACKGROUND

Revision total knee arthroplasty (TKA) for arthrofibrosis is fraught with challenges. Because rotating-hinge (RH) prostheses do not rely on ligaments for stability, a more aggressive soft-tissue release is possible. The goal of this study was to report arc of motion, Knee Society scores, and implant survivorship in patients with arthrofibrosis revised with an RH.

METHODS

Thirty-four patients revised with an RH for arthrofibrosis were matched to 68 patients revised without an RH. The mean age was 63 years, 62% were female, mean body mass index was 31 kg/m², and mean follow-up was 6 years (range, 2-15 years).

RESULTS

The mean arc of motion increased 20° (74°-94°) in the RH group versus 12° (87°-99°) in the non-RH group (P = .048). Two manipulations under anesthesia were performed in the RH group compared to 9 in the non-RH group (P = .2). Knee Society scores increased significantly in both groups (P = .01 and P < .001, respectively). Survivorship free of revision for aseptic loosening at 10 years was 83% in the RH group versus 96% in the non-RH group (P = .44). Survivorship free of any revision at 10 years was 54% in the RH group and 90% in the non-RH group (P = .03). Forty percent of the revisions in the RH group were related to insert and bushing exchanges.

CONCLUSION

In this series, patients with arthrofibrosis revised to an RH TKA had a 20° improvement in arc of motion and manipulations under anesthesia were half as common. However, there was a higher risk of re-revision in the RH group.

LEVEL OF EVIDENCE

III.

[Total endoprosthetic replacement of femur, humerus and tibia]

Improvements in diagnostics and effectiveness of chemotherapy have resulted in most patients with primary malignant bone tumours being candidates for limb salvage surgery. Herewith, the use of modern modular tumour endoprostheses allows for the replacement of all big joints and even entire long bones such as the femur, humerus and tibia. In this article, we focus on individual prerequisites for and challenges with performing a total endoprosthetic reconstruction of the above-mentioned anatomic structures. Additionally, data from the literature with regards to functional outcome, problems and complications are presented.

Failure rates and functional results for intercalary femur reconstructions after tumour resection

PURPOSE

To compare the results for patients treated with intercalary endoprosthetic replacement (EPR) or intercalary allograft reconstruction for diaphyseal tumours of the femur in terms of: (1) reconstruction failure rates; (2) cause of failure; (3) risk of amputation of the limb; and (4) functional result.

METHODS

Patients with bone sarcomas of the femoral diaphysis, treated with en bloc resection and reconstructed with an intercalary EPR or allograft, were reviewed. A total of 107 patients were included in the study (36 EPR and 71 intercalary allograft reconstruction). No differences were found between the two groups in terms of follow-up, age, gender and the use of adjuvant chemotherapy.

RESULTS

The probability of failure for intercalary EPR was 36% at 5 years and 22% for allograft at 5 years (p = 0.26). Mechanical failures were the most prevalent in both types of reconstruction. Aseptic loosening and implant fracture are the main cause in the EPR group. For intercalary allograft reconstructions, fracture followed by nonunion was the most common complication. Ten-year risk of amputation after failure for both reconstructions was 3%. There were no differences between the groups in terms of the mean Musculoskeletal Tumor Society score (27.4, range 16-30 vs. 27.6, range 17-30).

CONCLUSIONS

We have demonstrated similar failure rates for both reconstructions. In both techniques, mechanical failure was the most common complication with a low rate of limb amputation and good functional results.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Analysis of Postural Stability and Daily Energy Expenditure to Manage Tumor Patients' Functional Expectation

Background

Advances in surgical techniques, implant technology, radiotherapy, and chemotherapy have increased the recovery chances of patients with bone sarcomas. Accordingly, patients' expectations on life quality have also increased, highlighting the importance of objective evaluation of the functional results of reconstruction.

Methods

Thirteen patients with distal femoral endoprosthesis, who had been followed for an average of 2.9 years were evaluated. Postural stability, daily energy expenditure, muscle power, and range of motion were the four parameters analyzed in this study. The Musculoskeletal Tumor Society (MSTS) score and Toronto Extremity Salvage Score (TESS) were used to assess postoperative function and examine correlations with other parameters.

Results

Patients had sedentary activities in 84% of their daily lives. They exhibited a slower speed in the walk across test and a higher sway velocity in the sit-to-stand test (p = 0.005). MSTS scores were significantly correlated with the daily energy expenditure and walking speed.

Conclusions

Objective functional results acquired from various clinics will provide significant data to compare reconstruction techniques, rehabilitation protocols, and surgical techniques. In this way, it will be possible to satisfy the expectations of patients that increase in relation to enhanced recovery.

Results and functional outcomes of en-bloc resection and vascular reconstruction in extremity musculoskeletal tumors

Objectives

This paper aims to evaluate the extremity function and vascular outcome after limb-sparing surgery for extremity musculoskeletal tumors invading vascular structure required reconstruction.

Methods

Of the 507 patients with musculoskeletal tumors, who underwent surgery between 2004 and 2007, 17 (3,3%) patients with major vessel involvement were included in the study. The mean age was 37.8 ± 14.5, with a female/male ratio of 8/9. Thirteen (76.4%) patients had Stage IIb disease, and 2 (11,7%) patients had Stage III disease. In 2 (11,7%) patients have locally aggressive tumor that had Stage 3. Fifteen (88.2%) of the cases involved lower extremity, whilst 2 (11.8%) of them involved upper extremity. An arterial reconstruction was carried out in all patients. Wide tumor resection and endoprosthetic reconstruction were performed in 6 (35.2%) patients. Other 11 (65.8%) patients were treated with wide resection and soft tissue reconstruction. Postoperative data included; perioperative morbidities such as bleeding, infection, graft thrombosis, rupture, metastatic local recurrence and mortality. Ankle brachial index (ABI) and color-flow-duplex-scan (CFDS) were done at the final follow-up of the study, in order to prove the efficacy of reconstruction. Functional outcome was evaluated with International Society of Limb Salvage (ISOLS) criteria.

Results

The mean follow-up was of 39 months (range 3–120). Perioperative complications were arterial graft thrombosis occurred in 3 (17.6%) patients treated acutely with thrombectomy, uncontrolled deep wound infection occurred in 2 patients whom extremities were amputated.

The most frequent complication after surgery was limb edema according to possibly venous and lymphatic obstruction, staged as C1, C2 and C3 disease was established in 6 patients (two patients in each group), and 1 patient was classified as C6 disease. Three (17.6%) patients had local recurrence (1/3 patient died and 2/3 (11.7%) patients underwent transfemoral amputation). At the last follow-up, 9 (52.9%) patients were alive without evidence of disease, 8 (47.1%) patients were died due to primary disease. There were 8 (47.1%) patients alive with an intact limb. Although functional outcome scores were satisfactory, emotional acceptance scores were low. The limb salvage probability was 74.0%.

Conclusion

Limb-sparing oncological surgery in musculoskeletal tumors with vascular invasion provides a satisfactory limb function, which may lead to an improved life quality. Arterial reconstruction has a high rate of patency in the long term. The surgeon should be aware of early perioperative complication related to vascular reconstruction and infection that effect on the rate of extremity survival.

Level of evidence

Level IV, Therapeutic study

Single stage reconstruction of post traumatic and post excisional composite perigenual defects using chimeric pedicled propelled osteomyocutaneous fibula flap

INTRODUCTION

Composite perigenual defects (CPGDs) are exacting the expertise of the reconstructive surgeons. Segmental skeletal defects continue to be a challenge for both orthopedic and plastic surgeons. There are many techniques available for the reconstruction of segmental skeletal defects in the perigenual region. This study explores the outcomes of pedicled chimeric propelled osteomyocutaneous fibula flap reconstruction of post traumatic and post excisional composite perigenual defects (CPGDs) MATERIALS AND METHODS: It was a retrospective study conducted from 2011 to 2016 including 16 patients (5 post excisional defects and 11 post traumatic defects). 14 males and 2 females were included. Ages of the patients were ranging from 24 to 46 years. All had their CPGDs reconstructed with chimeric pedicled propelled fibula osteomyocutaneous flap RESULTS: All 15 patients on an average of 26 months follow-up assumed pain free unrestrictive walking. Fracture of hardware and transferred fibula occurred in one case 2 ^1/2 years following the surgery. Other patients had good functional recovery in an average of 26 months follow up. The average MSTS score of 15 patients was 23.9.

CONCLUSION

This anatomically construed procedure will be addendum to the armamentarium of reconstruction in both post excisional limb salvage milieu and secondary posttraumatic context for the perigenual composite defects. With high healing potential, infection culling capacity, high osteogenic potential and good supportive hardwares the pedicled osteomyocutaneous fibula flap may usher in better outcome in composite perigenual defects reconstruction.

Tibia Adamantinoma Resection and Reconstruction with a Custom-Made Total Tibia Endoprosthesis: A Case Report with 8-Year Follow-Up

This case study describes a total tibia resection and reconstruction with a custom-made endoprosthetic replacement (EPR) and a long-term, 8-year follow-up. The patient underwent a total tibia adamantinoma resection in 2009. Reconstruction was performed with a custom-made total tibia EPR, where both the knee joint and ankle joint were reconstructed. Two muscle flaps, latissimus dorsi free flap and a pedicled medial gastrocnemius flap, were used for soft tissue reconstruction. The patient returned to normal life as a kindergarten teacher, without complications for eight years. This case demonstrated the importance of successful multidisciplinary teamwork in close collaboration with industry. In our best knowledge, no over 2 years of follow-up of total tibia replacement reports have been published.

Implant Survival and Complication Profiles of Endoprostheses for Treating Tumor Around the Knee in Adults: A Systematic Review of the Literature Over the Past 30 Years

BACKGROUND

Endoprosthetic replacement has become the mainstream method of reconstruction after tumor resection around the knee for decades, but there is a lack of comprehensive review evaluating the implant outcomes. We performed a systematic review to analyze the implant survival and complication profiles of distal femoral replacement (DFR) and proximal tibial replacement (PTR) in adults, and to evaluate the effects of different fixation methods and hinge mechanisms.

METHODS

A systematic review of 40 studies with 4748 DFR cases and 1713 PTR cases was performed after searching the PubMed and EMBASE databases. Results of the implant longevity, complications, and other relevant data were extracted, recategorized, and analyzed. An additional review of 227 cases of Compress DFR from 6 studies was also performed.

RESULTS

The mean 5-, 10-, 15-, and 20-year implant survival rates of DFR were 78.3%, 70.1%, 61.6%, and 38.3%, slightly higher than those of PTR (75%, 60%, 55.3%, and 25.1%). Aseptic loosening (8.8%) and infection (8.5%) were the most devastating complications in DFR, while in PTR it was infection (16.8%). Cemented or cementless fixation did not significantly affect implant survival or aseptic loosening rate. Rotating-hinge mechanism might improve long-term implant survival and reduce bushing wear, but not necessarily prevented aseptic loosening. The series Kotz modular femur and tibia replacement system/Howmedica modular replacement system/global modular replacement system was one of the most durable implants. The Compress DFR showed no superiority in implant survival and complication profiles over other brands of endoprostheses.

CONCLUSION

Short-term to mid-term implant survival of adult tumor endoprostheses around the knee is acceptable but long-term outcome remains unsatisfactory. Efforts should be made in reducing loosening and infection.

Tumour endoprosthesis replacement in the proximal tibia after intra-articular knee resection in patients with sarcoma and recurrent giant cell tumour

PURPOSE

Proximal tibia replacements are commonly associated with post-operative complications and poor functional results due to an insufficiency of the extensor mechanism.

METHODS

This study evaluated the clinical results with a special emphasis of the extensor mechanism reconstruction with a reattachment tube and complications after intra-articular resection of the proximal tibia and reconstruction with a tumour endoprosthesis (MUTARS®) in 98 patients (median age 18 years) with malignant bone tumours or giant cell tumours.

RESULTS

Kaplan-Meier analysis showed that the limb survival rates were 94.9, 90.5 and 74.5% at one, two and ten years, respectively. Periprosthetic infection was the most common reason for secondary amputation (eight patients). The cumulative incidence rates of prosthetic failure (Henderson II-IV) were 18% at two years and 29% at five years post-operatively. An active extension deficit of more than 10° was noted in six patients only.

CONCLUSIONS

These results suggest that limb salvage with tumour prostheses after intra-articular resection can achieve good functional results with an active extension of the knee in the majority of patients. While mechanical complications can be treated successfully with revision surgery, periprosthetic infection continues to be the main reason for secondary amputation.

When Do Orthopaedic Oncologists Consider the Implantation of Expandable Prostheses in Bone Sarcoma Patients?

Introduction

Indications discussed for the implantation of expandable prostheses in bone sarcoma patients are unclear. This survey aimed to analyse common practice with this implant type in orthopaedic oncology.

Methods

A web-based survey was sent to 98 orthopaedic oncology surgeons. Factors reported in literature to influence the decision on the implantation of a growing prosthesis were covered in individual questions and three case scenarios.

Results

The completion rate of the survey was 45% (n = 44). Twenty-seven of 44 surgeons (61%) had implanted between 1 and 15 expandable prostheses within three years. The minimum median patient age was 6.5 years, and 3–5 cm of predicted growth deficit was the minimum before implanting a growing prosthesis. One-third of surgeons do not use growth calculation methods. Two out of three surgeons would rather not implant a growing prosthesis in children with metastatic disease.

Conclusions

Our survey confirmed the literature with 3-4 cm as the minimum estimated growth deficit. The minimum age for the implantation of a growing prosthesis is approx. 6.6 years, and therefore the patients are younger than those reported in previous publications. One-quarter of orthopaedic surgeons do not use growing prostheses at all. It remains unclear whether growing prostheses are indicated in patients with metastatic disease.

Survival, complications and functional outcomes of cemented megaprostheses for high-grade osteosarcoma around the knee

PURPOSE

We initiated a retrospective study on the long-term survival of cemented endoprostheses for bone tumours around the knee to answer the following questions: (1) What was the survival of these patients? (2) What was the overall survival of cemented prostheses around the knee? (3) What types of failures were observed in these reconstructions? (4) Did the survival and complications vary according to the site of the implant? (5) What was the functional result after cemented prosthesis replacement around the knee?

METHODS

From January 2006 to December 2013, 108 consecutive patients with an average age of 25 years, who had mature bone development as evidenced by imaging examinations, underwent 108 cemented endoprosthetic knee replacements for osteosarcoma resection. All patients received neoadjuvant chemotherapy using a multi-drug protocol consisting of high dose methotrexate (HDMTX), doxorubicin (ADM), cisplatin (DDP) and high dose ifosfamide (HDIFO). When extensor mechanism reconstruction was required, we ran nonabsorbable sutures through designated holes in the tibial component to fix detached hamstrings and the remaining ligaments in an imbricated fashion as well as reinforced the reconstruction with a medial gastrocnemius flap. Seventy-two (72/108, 66.7%) lesions were located in the distal femur and 36 (36/108, 33.3%) lesions at the proximal tibias. Nineteen patients were staged as IIA and 89 as IIB according to the Enneking staging system. The average follow-up was 53.3 months (range 12-125 months), with a minimum oncological follow-up of one year. Survival, prosthetic failure, complications and functional outcomes were recorded and reassessed at every visit after the primary operation.

RESULTS

At the final follow-up, the oncologic results showed that 33 patients died from metastases, and local recurrence occurred in ten patients. The estimated overall five-year and eight-year survival rates were 71% (95% CI: 62.4-79.65%) and 67.2% (95% CI: 58-76.4%), respectively. In this study, a total of 51 complications occurred in 45 patients, and at the end of follow-up, 59 patients had prostheses in situ. The estimated overall five-year and eight-year implant survival rates were 77.7% (95% CI: 67.9-87.5%) and 54.5% (95% CI: 31.4-77.6%), respectively, when patients who died with their original prostheses were censored. In total, 21 (21/108, 19.4%) implants failed, five due to infections (5/21), eight due to aseptic loosening (8/21), four due to local recurrence (4/21), three due to structural failure (3/21) and one due to soft tissue failure (1/21). The average Musculoskeletal Tumor Society Score (MSTS) at the most recent follow-up was 22.9 (9-30) points on a 30-point scale, which indicated an excellent or good functional outcome. Analysis of the results based on implant site revealed a slight difference of the estimated five-year prosthesis survival between implants located in the distal femur and those located in the proximal tibia [86.1% (95% CI: 75.5-97%) versus 66.9% (95% CI: 49.8-83.9%); P = 0.09]. However, the functional outcomes and complication rates of prostheses located in the distal femur were both better than those located in the proximal tibia.

CONCLUSIONS

With effective management strategies for complications, cemented endoprosthetic reconstruction of the proximal tibia and distal femur using an extensor mechanism reconstruction technique provides a reliable method of reconstruction following tumour resection around the knee. Level of Evidence Level IV, therapeutic study.

Rotating hinge prosthesis for complex revision total knee arthroplasty: A review of the literature

INTRODUCTION

The rotating hinge prosthesis was originally used and designed as a primary total knee arthroplasty implant, but was hampered due to poor outcomes and catastrophic failures. Newer rotating hinge implants can be utilized in complex revision total knee arthroplasties when appropriately indicated, but their outcome data is very difficult to interpret due to the strict and varied indications for use and subsequently small number of procedures performed. The goal of this review is to evaluate the current evidence on large cohort, rotating hinge knee prostheses used in the revision setting, in order to provide a clearer understanding of the indications, outcomes and complications.

METHODS

The PubMed database was utilized to search the available literature regarding "hinged knee," or "rotating hinge" devices. Exclusion criteria included papers focusing on primary arthroplasty, revision for oncologic issues, one-stage revision for infection or studies with less than fifty cases.

RESULTS

Review of 115 abstracts after initial search, led to ten studies in the literature that met our inclusion and exclusion criteria. The data shows that rotating hinge knee implants have good survivorship ranging from 51% to 92.5% at 10 years post-operatively. Complication rates range from 9.2% to 63% with infection and aseptic loosening as the most common complications.

CONCLUSION

Rotating hinge knee prostheses are most commonly indicated for infection, aseptic loosening, instability and bone loss in the literature. They have good outcome scores and survivorship, but continue to have high complication and revision rates. The implant is a good option when utilized appropriately for patients that are not candidates for less constrained devices.