Comparison between uncemented and cemented fixation for the tibial component in distal femoral replacement: a clinical and radiological study

Larger stem to bone diameter ratio predicts lower cemented endoprosthesis failure

BACKGROUND AND OBJECTIVES

With continued advances in treatment options, patients with endoprosthetic reconstruction are living longer and consequently relying upon their devices for a longer duration. Major causes of endoprosthesis failure include aseptic loosening and mechanical failure. In the setting of tumor resection, loss of bone stock and use of radiation therapy increase the risk for these complications. As such, considerations of remaining native bone and stem length and diameter may be increasingly important. We asked the following questions: (1) What was the overall rate of endoprosthesis failure at a minimum of 5-year follow-up? (2) Does resection length increase implant failure rates? (3) Does implant size and its ratio to cortical width of bone alter implant failure rates?

METHODS

We retrospectively analyzed patient outcomes at a single institution between the years of 1999-2022 who underwent cemented endoprosthetic reconstruction at the hip or knee and identified 150 patients. Of these 150, 55 had a follow-up of greater than 5 years and were used for analysis. Radiographs of these patients at time of surgery were assessed and measured for resection length, bone diameter, stem diameter, and remaining bone length. Resection percentage, and stem to bone diameter ratios were then calculated and their relationship to endoprosthesis failure were analyzed.

RESULTS

Patients in this cohort had a mean age of 55.8, and mean follow-up of 59.96 months. There were 78 distal femoral replacements (52%), 16 proximal femoral replacements (10.7%), and 56 proximal tibial replacements (37.3%). There were five patients who experienced aseptic loosening and six patients who experienced mechanical failure. Patients with implant failure had a smaller mean stem to bone diameter (36% vs. 44%; p = 0.002). A stem to bone diameter of 40% appeared to be a breaking point between success and failure in this series, with 90% of patients with implant failure having a stem: bone ratio less than 40%. Stem to bone ratio less than 40% increased risk for failure versus stems that were at least 40% the diameter of bone (6/19 [31.6%] vs. 0/36 [0%]; odds ratio 0.68; p < 0.001). Resection length did not appear to have an impact on the rates of aseptic loosening and mechanical failure in this series.

CONCLUSIONS

Data from this series suggests a benefit to using stems with a larger diameter when implanting cemented endoprostheses at the hip or knee. Stems which were less than 40% the diameter of bone were substantially more likely to undergo implant failure.

The Impact of Implant Fixation Type on Reoperation Rates Following Endoprosthetic Reconstruction Surgery

BACKGROUND

Prospective evidence supporting the use of cemented or uncemented implants in endoprosthetic reconstruction is lacking. The present study aimed to determine the effect of cemented fixation compared with uncemented fixation on the rate of all-cause reoperation at 1 year postoperatively.

METHODS

This is a secondary analysis of the Prophylactic Antibiotic Regimens In Tumor Surgery (PARITY) trial. A total of 503 patients who underwent surgical excision and endoprosthetic reconstruction of a lower-extremity bone tumor were included in this analysis. A multivariate Cox proportional hazards model was utilized to assess the independent relationship between fixation group and implant survivorship, with all-cause reoperation as the end point.

RESULTS

There were 388 cemented implants and 115 uncemented implants. Participants had a mean age of 42.7 years (standard deviation, 22.0 years), and 59% were male. Overall, 131 reoperations were identified over the 1-year follow-up period. There were no significant differences found in all-cause reoperation (hazard ratio [HR], 1.05; 95% confidence interval [CI], 0.70 to 1.57; p = 0.761), septic reoperation, or aseptic reoperation between cemented and uncemented fixation at 1 year postoperatively. The Cox regression analysis demonstrated that total operative time (HR per hour, 1.10; 95% CI, 1.02 to 1.20; p = 0.019) was an independent predictor of reoperation. The risk of reoperation was lower in patients with benign aggressive disease (HR, 0.11; 95% CI, 0.02 to 0.80; p = 0.029) or metastatic bone disease (HR, 0.30; 95% CI, 0.11 to 0.85; p = 0.023). Patients who underwent cemented fixation showed clinically meaningful functional improvement at 1 year postoperatively.

CONCLUSIONS

Cemented compared with uncemented fixation has no effect on 1-year all-cause reoperation rates in endoprosthetic reconstruction surgery. Further research is required to investigate the long-term survival of cemented versus uncemented implants.

LEVEL OF EVIDENCE

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

Distal femoral replacement - Does length matter? Mid-term results for distal femoral replacements

BACKGROUND

Review of mid-term results (five years) for tumour and revision arthroplasty surgery using the Stanmore METS® distal femoral replacement.

METHODS

Data were collected retrospectively for 90 patients for procedures performed between 2002 and 2019. Kaplan-Meier survivorship for implant was estimated at five years post-op. Endpoints for survivorship analysis included revision for any cause and as per Henderson classification. Log rank test was used to compare implant survival for different categorical variables. Musculo-Skeletal Tumour Society (MSTS) score was used to estimate function.

RESULTS

Overall implant survival at five years was 76% (95% CI 66-86). Implants with a short body (<= 45 mm) had significantly better implant survival [87% (95% CI 78-99)] compared to those with larger bodies [63% (95% CI 48-82)] (logrank test, p = 0.031). There was no significant difference in implant survival for tumour and revision arthroplasty patients (logrank test, p = 0.61). Mean MSTS scores (median follow-up = 3.5 years) for tumour and revision arthroplasty patient were 71% and 63% respectively (Wilcoxon rank test, p < 0.05). Higher total number of surgeries was a significant predictor of patient mortality [HR = 0.7 (95% CI 0.49-0.99)]. Longer bodies were a significant predictor of implant failure [HR = 3.2 (95% CI 1.05-10.53), p < 0.05].

CONCLUSION

Overall outcome of Stanmore METS® distal femoral replacement at five years following tumour and revision arthroplasty reconstruction is comparable to the other implants.

Outcomes of Cemented Distal Femoral Replacement Using "Line to Line" Technique With All-Polyethylene Tibial Implant for Tumors

BACKGROUND

Both cemented and cementless stemmed endoprosthetic implants have been used to reconstruct large skeletal defects after tumor resection with similar outcomes. In this study, we examined the oncologic, clinical, and functional outcomes in patients undergoing distal femur replacement using the French paradox technique.

METHODS

A total of 125 patients who underwent distal femur replacement between 1990 and 2019 using the line-to-line cementation technique were reviewed. Implant failure was recorded as per Henderson's classification. Functional outcomes were analyzed using the Musculoskeletal Tumor Society and Toronto Extremity Salvage Score scoring systems. The mean follow-up was 84 (1-350) months.

RESULTS

Aseptic loosening of the femoral stem was recorded in one patient at 21-years of follow-up. Twenty of 125 patients required bushing exchange for polyethylene wear, all after 10 years. Six tibial bearing component fractures were recorded in four patients while one femoral stem component Morse taper fractured. Two all-polyethylene cemented tibial implants were revised for polyethylene granuloma. Deep surgical site infection occurred in 13 patients, while six patients experienced local recurrence. Kaplan-Meier estimates for implant survival for all-cause revision were 85% at 1 year and 70% at 5 years. These estimates for femur or tibia loosening as an end point were 96% at 10 years and 90% at 15 years. The mean Musculoskeletal Tumor Society and Toronto Extremity Salvage Score scores at the last follow-up were 76% and 74%, respectively. Thirty-five patients died of disease progression.

CONCLUSION

The line-to-line cementation technique, used with all-polyethylene tibial implants, demonstrates low incidence of aseptic loosening at medium and long-term follow-ups.

LEVEL OF EVIDENCE

III.

Are Cemented Endoprosthetic Reconstructions Superior to Uncemented Endoprostheses in Terms of Postoperative Outcomes and Complications in Patients with Extremity-Located Bone Metastasis Scheduled for Adjuvant Radiotherapy?

BACKGROUND

Adjuvant radiotherapy frequently is used for prevention of recurrence following resection and endoprosthetic reconstruction of bone metastases. Besides this positive effect, radiotherapy can negatively affect both cemented and uncemented endoprostheses.

METHODS

We retrospectively analyzed 130 extremities of 115 patients who underwent resection and cemented or uncemented endoprosthetic reconstruction for bone metastasis, followed by postoperative radiation therapy. The functional improvement was assessed by Karnofsky Performance Scale and Musculoskeletal Tumor Society (MSTS) scoring. The radiological evaluation mainly included analysis of "loosening areas" which were defined as the regions of osteolysis between the stem of the endoprostheses and the cement or cortex. The complications resulting in reconstruction failure and patient survival were recorded.

RESULTS

A survival analysis revealed that 21 (18.3%) patients were alive with disease and 94 (81.7%) died of disease at the time of study. The mean last follow-up Karnofsky Performance Scale and MSTS scores of the whole study cohort were 78.69 ± 8.66 and 82.15 ± 9.06, respectively. There were 8 (6.15%) complications resulting in reconstruction failure, including aseptic loosening (2), femoral stem breakage (2), periprosthetic fracture (2), and infection (2). The number and time of complications did not show a significant difference between the cemented and uncemented groups (P > .05).

CONCLUSION

This study demonstrated that there was no significant difference in complication rates of cemented or uncemented endoprosthetic reconstructions in patients with extremity-located bone metastases scheduled for adjuvant radiotherapy. The only result in favor of cemented prostheses was significantly higher MSTS functional scores at last follow-up.

The Treatment of Periprosthetic Distal Femoral Fractures After Total Knee Replacement: A Critical Analysis Review

Periprosthetic distal femoral fracture after total knee arthroplasty carries substantial morbidity and mortality regardless of fixation technique. Surgical treatment is favored in most patients compared with conservative therapy because of high rates of nonunion, malunion, and reoperation after casting or bracing. Internal fixation techniques including retrograde intramedullary nailing and locked plating are favored for surgical treatment in most fractures when bone stock in the distal fragment allows for appropriate fixation. In the setting of deficient distal femoral bone stock or femoral component loosening, revision arthroplasty with distal femoral replacement is the favored technique. Further studies with regard to the use of intramedullary nailing, locked plating, and distal femoral replacement are necessary to refine the indications for each technique and to define the use of combinations of these fixation techniques.

Advances in tumour endoprostheses: a systematic review

Tumour endoprostheses have facilitated limb-salvage procedures in primary bone and soft tissue sarcomas, and are increasingly being used in symptomatic metastases of the long bones.

The objective of the present review was to analyse articles published over the last three years on tumour endoprostheses and to summarize current knowledge on this topic. The NCBI PubMed webpage was used to identify original articles published between January 2015 and April 2018 in journals with an impact factor in the top 25.9% of the respective category (orthopaedics, multidisciplinary sciences).

The following search-terms were used: tumour endoprosthesis, advances tumour endoprosthesis, tumour megaprosthesis, prosthetic reconstruction AND tumour. We identified 347 original articles, of which 53 complied with the abovementioned criteria.

Articles were categorized into (1) tumour endoprostheses in the shoulder girdle, (2) tumour endoprostheses in the proximal femur, (3) tumour endoprostheses of the knee region, (4) tumour endoprostheses in the pelvis, (5) (expandable) prostheses in children and (6) long-term results of tumour endoprostheses.

The topics of interest covered by the selected studies largely matched with the main research questions stated at a consensus meeting, with survival outcome of orthopaedic implants being the most commonly raised research question.

As many studies reported on the risk of deep infections, research in the future should also focus on potential preventive methods in endoprosthetic tumour reconstruction.

Cite this article: EFORT Open Rev 2019;4:445-459. DOI: 10.1302/2058-5241.4.180081