Rate of Revision Surgery and Associated Risk Factors After Primary Arthroscopic ACL Repair With Additional Suture Augmentation.

Background: Recent studies have suggested promising patient-reported outcomes after primary anterior cruciate ligament (ACL) repair with additional suture augmentation (SA). Purpose: To evaluate the risk for revision surgery and identify patient- and injury-related risk factors after ACL repair with SA in a large patient cohort subject to strict patient selection. Study Design: Case-control study; Level of evidence, 3. Methods: Included were 86 patients (61 female; 93% follow-up rate) who underwent arthroscopic ACL repair with SA between January 2017 and March 2019 by a single surgeon and had a minimum follow-up of 24 months. Patients were selected for surgery with regard to time to surgery (preferably on the day of injury), tear pattern (limited to Sherman types 1 and 2), and tissue quality (intact synovial coverage). Postoperatively, the patients who needed revision surgery were identified and compared with patients who did not undergo revision surgery, using the Mann-Whitney U test for nonparametric analysis and the Student t test for parametric analysis. A Kaplan-Meier analysis was performed to investigate the survival rate of the ACL repair. Results: A total of 9 patients (10%; median age, 48 years; interquartile range [IQR], 27-50 years) underwent revision surgery at 12 months postoperatively (IQR, 8-25 months). The median follow-up of patients without revision surgery was 35 months (IQR, 33-44 months). The revision-free survival rate was 97% (95% CI, 93%-100%) after 1 year, 93% (95% CI, 88%-98%) after 2 years, and 90% (95% CI, 83%-97%) after 4 years. Patient-related factors-such as sex (P = .98), age at surgery (P = .459), body mass index (P = .352), and preinjury level of sports (P = .53)-had no significant impact on the survival rate of the ACL repair. Injury-related factors-such as concomitant injuries of the medial (P = .860) and lateral menisci (P = .414) and the medial (P = .801) and lateral collateral ligaments (P = .534) or same-day surgery compared with a delay of surgery of up to 18 days (P = .277)-had no significant impact on the survival rate of the ACL repair. Conclusion: The revision rate of primary ACL repair with SA at a 2-year follow-up was 10%. Patient- and injury-related factors were not associated with the survival rate of the ACL repair.

Patients Regularly Return to Medium- and Low-Impact Types of Sporting Activities Following Distal Femoral or Proximal Tibial Replacement After Resection of a Primary Bone Sarcoma.

BACKGROUND: Little is known about the resumption of sporting activities following megaprosthetic reconstruction of the distal femur and proximal tibia after resection of a bone sarcoma. Thus, the aims of our study were: (1) to assess the functional outcome; (2) to evaluate pre- and post-operatively performed sporting activities; and (3) to identify potential beneficial and limiting factors. METHODS: Between 1993 and 2015, a total of 230 patients underwent distal femoral replacement (DFR), and 96 patients underwent proximal tibial replacement (PTR). The exclusion criteria were death, amputation, living overseas, and a congenital disability. Functional outcome and sporting activities were assessed using the Musculoskeletal Tumor Society Score (MSTS), Toronto Extremity Salvage Score (TESS), Forgotten Joint Score (FJS), subjective knee value (SKV), the Tegner activity score (TS), and the modified weighted activity score (WAS). RESULTS: There were 93 patients who had a median follow-up of 182 months (interquartile range (IQR) 130 to 260) after DFR with the following median scores: MSTS 18 (IQR 12 to 23), TESS 75% (IQR 60 to 84), FJS 25 (IQR 8 to 40), SKV 53% (IQR 40 to 70), TS 3 (IQR 3 to 4), and WAS 4 (IQR 0 to 8). There were 42 patients who had a median follow-up of 193 months (IQR 137 to 244) after PTR had the following median scores: MSTS 17 (IQR 15 to 22), TESS 78% (IQR 68 to 88), FJS 32 (IQR 20 to 46), SKV 60% (IQR 40 to 70), TS 3 (IQR 3 to 4), and WAS 4 (IQR 1 to 10). Postoperatively, 61% of DFR and 76% of PTR patients participated in at least one sporting activity. CONCLUSIONS: The functional outcome is overall good with a regular resumption of sporting activities. Patients' age at surgery and higher preoperative sporting levels were associated with better functional outcomes and higher postoperative sporting activity.

Shoulder dislocations in professional male football (soccer): A retrospective epidemiological analysis of the German Bundesliga from season 2012/2013 until 2022/2023.

PURPOSE: Injuries exert a detrimental impact on the team performance in professional football. Shoulder dislocations are known for their severity and often cause substantial lay-off times. However, there is a notable gap in the general understanding regarding the frequency and convalescence of these events in professional football. Thus, the aims of this study were (1) to determine the incidence, (2) to evaluate return to competition (RTC) and redislocation events (RDEs) and (3) to identify relevant player-, match- and injury-related parameters. METHODS: All shoulder dislocations within the highest three German football leagues (1.-3. Bundesliga) during the seasons 2012/2013 until 2022/2023 were identified. Player-, injury- and match-related data were obtained by performing a media analysis. Data were analysed using descriptive statistics. p Value was set at 0.05. RESULTS: A total of 90 first-time shoulder dislocations in 89 players with a median age of 25 years (interquartile range [IQR]: 23-28) were available for analysis. The incidence was 9.1 per 1000 Bundesliga matches played and increased over time. Forty-four (49%) shoulder dislocations were treated conservatively and 46 (51%) operatively. Median RTC was 24 days (IQR: 12-43) following conservative and 103 days (IQR: 85-135) following surgical treatment (p < 0.001). Twenty-two (24%) players suffered a redislocation, of whom 13 (59%) underwent initial conservative and nine (41%) initial surgical treatment (not significant [n.s.]). RDE following conservative treatment was after a median of 4 months (IQR: 2-22) and 7 months (IQR: 3-23) following surgical treatment (n.s.). CONCLUSION: The incidence of shoulder dislocation within professional football is increasing and currently amounts to 9.1 per 1000 matches played. A conservative treatment leads to a quicker RTC, while frequency and time to RDE were similar regardless of treatment. The increasing incidence of shoulder dislocations in professional football necessitates an analysis of relevant injury mechanisms and the implementation of specific preventive measures. LEVEL OF EVIDENCE: Level III.

How shoulder immobilization after surgery influences daily activity - a prospective pedometer-based study.

PURPOSE: Immobilization, especially of the lower extremity, after orthopaedic surgery has been associated with reduced physical activity. Previous interventions from our study group showed even in young, healthy people reduced activity levels after immobilization of the shoulder. Therefore, this study investigates the change in physical activity due to shoulder immobilization after a reconstructive surgery. METHODS: This prospective study includes 40 patients undergoing surgery from May 2019 to December 2020. Daily activity was measured before surgery, after discharge and three weeks postoperatively each time for six days. Activity including step counts and active time were measured by Fitbit™ inspire. Range of motion before and after surgery as well as Pain (VAS) were documented. RESULTS: Steps became significantly less immediately postoperatively with an immobilized shoulder joint than before surgery (9728.8 vs. 6022.6, p < 0.05). At follow-up, the number of steps increased again, but still showed a significantly lower number of steps (mean 8833.2) compared to preoperative. Patients preoperatively showed mostly an "active" activity pattern, whereas postoperatively a "low active" behaviour predominated. The proportion of sedentary behaviour ("basal activity" and "limited activity") was almost three times higher postoperatively (12.5% vs. 30%). CONCLUSION: General physical activity is restricted during upper limb immobilization in adults. Therefore, activity-enhancing measures should be implemented in the early phase of rehabilitation after upper extremity surgery.

Endoprosthetic Reconstruction of the Proximal Humerus with an Inverse Tumor Prosthesis.

Reconstructing the proximal humerus after tumor removal is challenging due to muscle and bone loss. The current methods often result in poor shoulder function. This study assessed the long-term functional and oncological outcomes of using an inverse proximal humerus prosthesis in 46 patients with bone tumors. The results showed a mean range of motion of 62° in anteversion, 28° in retroversion, and 55° in abduction. Notably, 23 patients achieved over 90° of shoulder abduction, with an average of 140°. The median Musculoskeletal Tumor Society Score was 25. Complications included infection in two radiotherapy patients and single dislocations in seven patients. One patient with recurrent dislocations needed revision surgery. In conclusion, the use of the inverse proximal humerus prosthesis in bone tumor treatment yields excellent shoulder function and high patient satisfaction. This approach is especially beneficial for those with metastatic disease.

Distal Humeral Replacement in Patients with Primary Bone Sarcoma: The Functional Outcome and Return to Sports.

Distal humeral replacement (DHR) is a limb-salvage option for the endoprosthetic reconstruction of bone defects following the resection of a primary bone sarcoma. As primary bone sarcomas are only occasionally located around the distal humerus, there is a paucity of information regarding postoperative function, and patients' resumption of sporting activities. With advances in diagnostics and in surgical and oncological treatment leading to an increased patient life expectancy and higher quality of life, patients' functional outcome and return to sports activities are of increasing interest. Between 1997 and 2021, a total of 24 patients underwent DHR with a single-design modular implant at a tertiary sarcoma center. A total of 14 patients who died of their disease were excluded, leaving a study cohort of 10 patients, with a median age of 30 years on the day of surgery (IQR 20-37). At the last follow-up, after a median of 230 months (IQR 165-262), the median MSTS was 19 (IQR 13-24), the median TESS was 79 (IQR 66-87), the median SEV was 38% (IQR 24-53), the median TS was 6 (IQR 4-7), and the median WAS was 3 (IQR 1-8). Among the variables of gender, surgery on the dominant extremity, intraoperative nerve resection, extra-articular tumor resection, chemotherapy, radiotherapy, and revision surgeries, none were associated with a better/lower functional outcome score or return to sports activities. However, a higher level of sports performance prior to diagnosis (WAS > 10) was associated with a higher level of sports performance postoperatively (p = 0.044).

The Role of Single Positive Cultures in Presumed Aseptic Total Hip and Knee Revision Surgery-A Systematic Review of the Literature.

(1) Background: Prior to revision hip (THA) or knee arthroplasty (TKA), periprosthetic low-grade infection (PJI) should be ruled out. Despite advances in preoperative diagnosis, unsuspected positive cultures (UPCs) may occur in initially planned aseptic revisions. Particularly, single UPCs pose a diagnostic and therapeutic dilemma, as their impact on outcome is unclear and recommendations are heterogeneous. This review investigates the frequency of single UPCs and their impact on implant survivorship. (2) Methods: In July 2022, a comprehensive literature search was performed using PubMed and Cochrane Library search. In total, 197 articles were screened. Seven retrospective studies with a total of 5821 cases were able to be included in this review. (3) Results: Based on the cases included, UPCs were found in 794/5821 cases (14%). In 530/794 cases (67%), the majority of the UPCs were single positive. The most commonly isolated pathogens were coagulase negative Staphylococci and Cutibacterium acnes. Five of seven studies reported no influence on revision- or infection-free survival following a single positive culture. In two studies, single UPCs following THA revision were correlated with subsequent re-revision for PJI. (4) Conclusions: Single UPCs of a non-virulent pathogen following presumed aseptic TKA revision may be interpreted as contaminants. A single UPC following THA revision may be a risk factor for subsequent PJI. The role of systemic antibiotic treatment remains unclear, but it should be considered if other risk factors for PJI are present.

What Is the Risk of Dislocation and Revision in Proximal Femoral Replacement with Dual-mobility Articulation After Two-stage Revision for Periprosthetic Hip Infection?

BACKGROUND: Dislocation is a major complication of revision THA after two-stage exchange for periprosthetic joint infection (PJI). The likelihood of dislocation can be particularly high if megaprosthetic proximal femoral replacement (PFR) has been performed during a second-stage reimplantation. Dual-mobility acetabular components are an established way of reducing the instability risk in revision THA; however, the likelihood of dislocation for dual-mobility reconstructions in the setting of a two-stage PFR has not been studied systematically, although patients with these reconstructions might be at an increased risk. QUESTIONS/PURPOSES: (1) What is the risk of dislocation and revision for dislocation in patients who underwent PFR with a dual-mobility acetabular component as part of two-stage exchange for hip PJI? (2) What is the risk of all-cause implant revision and what other procedures were performed (apart from revision for a dislocation) in these patients? (3) What potential patient-related and procedure-related factors are associated with dislocation? METHODS: This was a retrospective study from a single academic center including procedures performed between 2010 and 2017. During the study period, 220 patients underwent two-stage revision for chronic hip PJI. Two-stage revision was the approach of choice for chronic infections, and we did not perform single-stage revisions for this indication during the study period. Thirty-three percent (73 of 220) of patients underwent second-stage reconstruction with a single-design, modular, megaprosthetic PFR because of femoral bone loss, using a cemented stem. A cemented dual-mobility cup was the approach of choice for acetabular reconstruction in the presence of a PFR; however, 4% (three of 73) were reconstructed with a bipolar hemiarthroplasty to salvage an infected saddle prosthesis, leaving 70 patients with a dual-mobility acetabular component and a PFR (84% [59 of 70]) or total femoral replacement (16% [11 of 70]). We used two similar designs of an unconstrained cemented dual-mobility cup during the study period. The median (interquartile range) patient age was 73 years (63 to 79 years), and 60% (42 of 70) of patients were women. The mean follow-up period was 50 ± 25 months with a minimum follow-up of 24 months for patients who did not undergo revision surgery or died (during the study period, 10% [seven of 70] died before 2 years). We recorded patient-related and surgery-related details from the electronic patient records and investigated all revision procedures performed until December 2021. Patients who underwent closed reduction for dislocation were included. Radiographic measurements of cup positioning were performed using supine AP radiographs obtained within the first 2 weeks after surgery using an established digital method. We calculated the risk for revision and dislocation using a competing-risk analysis with death as a competing event, providing 95% confidence intervals. Differences in dislocation and revision risks were assessed with Fine and Gray models providing subhazard ratios. All p values were two sided and the p value for significance was set at 0.05. RESULTS: The risk of dislocation (using a competing-risks survivorship estimator) was 17% (95% CI 9% to 32%) at 5 years, and the risk of revision for dislocation was 12% (95% CI 5% to 24%) at 5 years among patients treated with dual-mobility acetabular components as part of a two-stage revision for PJI of the hip. The risk of all-cause implant revision (using a competing-risk estimator, except for dislocation) was 20% (95% CI 12% to 33%) after 5 years. Twenty-three percent (16 of 70) of patients underwent revision surgery for reinfection and 3% (two of 70) of patients underwent stem exchange for a traumatic periprosthetic fracture. No patients underwent revision for aseptic loosening. We found no differences in patient-related and procedure-related factors or acetabular component positioning for patients with dislocation with the numbers available; however, patients with total femoral replacements had a higher likelihood of dislocation (subhazard ratio 3.9 [95% CI 1.1 to 13.3]; p = 0.03) and revision for a dislocation (subhazard ratio 4.4 [95% CI 1 to 18.5]; p = 0.04) than those who received PFR. CONCLUSION: Although dual-mobility bearings might be an intuitive potential choice to reduce the dislocation risk in revision THA, there is a considerable dislocation risk for PFR after two-stage surgery for PJI, particularly in patients with total femoral replacements. Although the use of an additional constraint might appear tempting, published results vary tremendously, and future studies should compare the performance of tripolar constrained implants to that of unconstrained dual-mobility cups in patients with PFR to reduce the risk of instability. LEVEL OF EVIDENCE: Level III, therapeutic study.

Function and return to sports after proximal humeral replacement in patients with primary bone sarcoma.

BACKGROUND: Improved patient and limb survival rates have led to an increased interest in the functional outcome and return to sports of patients undergoing megaprosthetic reconstruction in musculoskeletal oncology. This study evaluates the functional outcome and postoperatively performed level of sports in patients undergoing proximal humeral replacement (PHR) following resection of a primary bone sarcoma and identifies potential beneficial and limiting factors. PATIENTS AND METHODS: Between 2007 and 2020, a total of 606 patients underwent resection of a primary bone sarcoma and reconstruction with a single-design modular implant. For 112 (18%) patients, the location of the tumour was the proximal humerus. Exclusion criteria were death (n = 65), patients living overseas (n = 8), and subsequent amputation (n = 1), leaving 38 patients for evaluation, of whom 32 were available for the study (13 women, median age 42 years). Clinical data regarding oncological and surgical treatment as well as subsequent complications were obtained from the patients' electronic medical records. Functional outcome was determined using the Musculoskeletal Tumor Society Score (MSTS) and Toronto Extremity Salvage Score (TESS) as well as the Subjective Shoulder Value (SSV). Return to sports was assessed using the Tegner Activity Score (TS) and the modified Weighted Activity Score (WAS). RESULTS: At the last follow-up after a median of 30 months (IQR 22-58), median MSTS was 18 (IQR 12-24), median TESS was 80% (IQR 69-87), median SSV was 35% (IQR 10-58), median TS was 5 (IQR 4-6) and median WAS was 5 (IQR 0-10). Preservation of the axillary nerve, a reverse shoulder reconstruction and a WAS of > 10 prior to surgery were associated with better functional outcome and return to sports activity scores. CONCLUSION: Following PHR, good to excellent functional outcomes are possible, and patients regularly return to participate in sports activities-most commonly in low-impact types of sports, but some individuals are even able to participate in high-impact sports activities. LEVEL OF EVIDENCE: IV.

MUTARS® Humero pro Femur replacement: A novel reconstructive procedure after malignant bone tumor resection of the femur in young children.

Limb-preserving surgery in young children suffering malignant bone tumor of the femur is challenging due to the specific anatomical conditions. Extendable tumor endoprostheses are often oversized, while custom-made endoprostheses do not provide the intraoperatively required variability regarding reconstruction length. Allo- and autograft replacements, on the other hand, show high complication and revision rates. We report a novel reconstructive procedure after resection of malignant bone tumors of the femur in young children, and present our preliminary results of this technique.

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

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.

Evaluation of a novel classification system to predict local recurrence in sarcoma patients undergoing hemipelvectomy with iliosacral resection.

AIMS: Iliosacral sarcoma resections have been shown to have high rates of local recurrence (LR) and poor overall survival. There is also no universal classification for the resection of pelvic sarcomas invading the sacrum. This study proposes a novel classification system and analyzes the survival and risk of recurrence, when using this system. METHODS: This is a retrospective analysis of 151 patients (with median follow-up in survivors of 44 months (interquartile range 12 to 77)) who underwent hemipelvectomy with iliosacral resection at a single centre between 2007 and 2019. The proposed classification differentiates the extent of iliosacral resection and defines types S1 to S6 (S1 resection medial and parallel to the sacroiliac joint, S2 resection through the ipsilateral sacral lateral mass to the neuroforamina, S3 resection through the ipsilateral neuroforamina, S4 resection through ipsilateral the spinal canal, and S5 and S6 contralateral sacral resections). Descriptive statistics and the chi-squared test were used for categorical variables, and the Kaplan-Meier survival analysis were performed. RESULTS: Resections were S1 in 25/151 patients (17%), S2 in 70/151 (46%), S3 in 33/151 (22%), S4 in 77/151 (11%), S5 in 4/151 (3%), and S6 in 2/151 (1%). An internal hemipelvectomy was performed in 113/151 patients (75%), and 38/151 patients (25%) had an external hemipelvectomy. The predominant types of sarcoma were high-grade osteosarcoma in 48/151 patients (32%), chondrosarcoma in 41/151 (27%), Ewing sarcoma in 33/151 (22%), pleomorphic sarcoma in 17/151 (11%), and others in 2/151 (8%). LR was found in 24/151 patients (15%) with S3, S5, with S6 resections showing the highest rate of LR (p = 0.038). Overall, 19/151 patients (16%) had evidence of metastastic disease at the time of surgery and these patients showed poorer survival when compared to patients with no metastasis. CONCLUSION: The proposed classification can help to report and compare different surgical and reconstructive approaches in these difficult cases who are still have a considerable risk of LR. Cite this article: Bone Joint J 2022;104-B(2):290-296.

Revision TKA with a distal femoral replacement is at high risk of reinfection after two-stage exchange for periprosthetic knee joint infection.

PURPOSE: Megaprosthetic distal femoral reconstruction (DFR) is a limb-salvage procedure to address bone loss following two-stage revision for periprosthetic knee joint infection (PJI). The purpose of this study was to analyze the survival of DFR compared to hinged total knee arthroplasty (TKA). It was hypothesized that DFR was associated with a poorer survival. METHODS: In this retrospective single-center study, 97 subjects who underwent two-stage revision of chronic knee PJI were included. Among these, 41 were DFR. The diagnosis of PJI was established using the Musculoskeletal Infection Society (MSIS) criteria. Implant survival was calculated using Kaplan-Meier method and compared with the log-rank test as well as multivariate Cox regression at a minimum follow-up period of 24 months. RESULTS: The median follow-up period was 59 (interquartile range (IQR) 45-78) months. Overall, 24% (23/97) of patients required revision surgery for infection. The infection-free survival of rotating hinge revision TKA was 93% (95% Confidence Interval (CI) 86-100%) at five years compared to 50% (95% CI 34-66%) for DFR. In multivariate analysis, the risk factors for reinfection were DFR reconstruction (HR 4.7 (95% CI 1-22), p = 0.048), length of megaprosthesis (HR 1.006 (95% CI 1.001-1.012), p = 0.032) and higher BMI (HR 1.066, 95% CI 1.018-1.116), p = 0.007). 10% (4/41) of patients undergoing DFR underwent amputation to treat recurrent infection. CONCLUSION: Megaprosthetic DFR as part of a two-stage exchange for PJI is a salvage treatment that has a high risk for reinfection compared to non-megaprosthetic TKA. Patients must therefore be counseled accordingly. LEVEL OF EVIDENCE: Retrospective observational study, Level IV.

The Bateman-Type Soft Tissue Reconstruction around Proximal or Total Humeral Megaprostheses in Patients with Primary Malignant Bone Tumors-Functional Outcome and Endoprosthetic Complications.

We aimed to evaluate the functional outcome and endoprosthetic complications following the Bateman-type soft tissue reconstruction around proximal or total humeral replacements in patients undergoing resection of a primary malignant bone tumor. Between September 2001 and December 2018, a total of 102 patients underwent resection of a primary malignant bone tumor and subsequent reconstruction with a modular humeral megaprosthesis in our department. Fifteen (15%) of these patients underwent a Bateman-type soft tissue reconstruction and were included in this retrospective study. The median Musculoskeletal Tumor Society (MSTS) score was 21, the median Toronto Extremity Salvage Score (TESS) was 70, and the median American Shoulder and Elbow Surgeons (ASES) score was 72. Fifty-three percent (8/15) of all patients required a revision surgery after a median time of 6 months. There were 2 soft tissue failures, 3 infections and 3 tumor recurrences. The revision-free implant survivorship amounted to 53% (95% confidence interval (CI) 28-81) after 1 year and 47% (95% CI 22-73) at last follow-up. The Bateman-type reconstruction is a feasible option for soft tissue reconstruction but functional outcome is overall limited and the risk for revision surgery within the first postoperative year is high.

Periprosthetic Stress Shielding of the Humerus after Reconstruction with Modular Shoulder Megaprostheses in Patients with Sarcoma.

(1) Background: Modular megaprosthetic reconstruction using a proximal humerus replacement has emerged as a commonly chosen approach after bone tumor resection. However, the long-term risk for revision surgery is relatively high. One factor that might be associated with mechanical failures is periprosthetic osteolysis around the stem, also known as stress shielding. The frequency, potential risk factors, and the effect on implant survival are unknown. (2) Methods: A retrospective single-center study of 65 patients with sarcoma who underwent resection of the proximal humerus and subsequent reconstruction with a modular endoprosthesis. Stress shielding was defined as the development of bone resorption around the prosthesis stem beginning at the bone/prosthesis interface. The extent of stress shielding was measured with a new method quantifying bone resorption in relation to the intramedullary stem length. All patients had a minimum follow-up of 12 months with conventional radiographs available and the median follow-up amounted to 36 months. (3) Results: Stress shielding was observed in 92% of patients (60/65). The median longitudinal extent of stress shielding amounted to 14% at last follow-up. Fifteen percent (10/65) showed bone resorption of greater than 50%. The median time to the first radiographic signs of stress shielding was 6 months (IQR 3-9). Patients who underwent chemotherapy (43/65) showed a greater extent of stress shielding compared to those without chemotherapy. Three percent (2/65) of patients were revised for aseptic loosening, and one patient had a periprosthetic fracture (1/65, 1.5%). All these cases had >20% extent of stress shielding (23-57%). (4) Conclusions: Stress shielding of the proximal humerus after shoulder reconstruction with modular megaprosthesis is common. It occurs within the first year of follow-up and might be self-limiting in many patients; however, about one third of patients shows progression beyond the first year. Still, mechanical complications were rare, but stress shielding might be clinically relevant in individual cases. The extent of stress shielding was increased in patients who underwent perioperative chemotherapy. Stress shielding can be quantified with an easy method using the stem length as a reference.

Melorheostosis of the Fossa Intercondylaris Femoris - A Case Report and Review of the Literature.

INTRODUCTION: Melorheostosis is a rare benign bone condition characterized by excessive segmental sclerosis of cortical bone being reminiscent of dripping candle wax. It typically affects the long bones and can cause impingement and nerve compression syndromes that may require surgical treatment. CASE REPORT: We report the case of a 49-year-old male patient with a 12-month history of the left-sided knee pain and a concomitant limitation of his left knee flexion to 90 degree. Radiographic and magnetic resonance imaging revealed the typical radiographic appearance of melorheostosis with an extraosseous lesion in the fossa intercondylaris femoris being causative for the limited knee range of motion. Following the resection of the extraosseous part of the lesion through a direct open approach, the patient is pain free with a maximum of 110 degree knee flexion at 12-month follow-up. CONCLUSION: Melorheostosis can present with manifold clinical manifestations that potentially require surgical treatment. Even in patients with a challenging localization of extraosseous lesions, a good to excellent functional outcome is possible.

Combined Transarterial Embolization and Percutaneous Sclerotherapy as Treatment for Refractory and Nonresectable Aneurysmal Bone Cysts.

PURPOSE: To evaluate the safety and effectiveness of combined transarterial embolization and percutaneous sclerotherapy in the treatment of refractory and nonresectable aneurysmal bone cysts (ABCs) as assessed by imaging and clinical outcomes. MATERIALS AND METHODS: This retrospective, single-center study included 16 consecutive patients (9 women and 7 men; median age, 17 years [range, 6-25 years]) who underwent combined transarterial embolization (using ethylene vinyl alcohol) and percutaneous sclerotherapy (using ethanol gel and polidocanol) for refractory and nonresectable ABCs. The median follow-up was 27.3 months (range, 6.7-47.5 months). Grade of mineralization (5-point Likert scale), grade of fluid-fluid levels (FFLs; 4-point Likert scale), and contrast-enhancing lesion volume were evaluated before and after treatment. The quality of life was determined before and after treatment using the Musculoskeletal Tumor Society (MSTS) score and the 36-Item Short Form Survey (SF-36) health questionnaire. RESULTS: A mean of 1.6 ± 0.7 transarterial embolizations and 3.2 ± 1.7 percutaneous sclerotherapies were performed. No adverse events were observed. All patients showed either partial or complete response; no patient showed ABC recurrence. The grade of mineralization (3.7 ± 0.7 after therapy vs 1.4 ± 0.5 at baseline; P < .0001) and grade of FFL (3.5 ± 0.8 after therapy vs 1.9 ± 0.6 at baseline; P < .0001) significantly improved after therapy compared with baseline. The mean contrast-enhancing lesion volume significantly decreased after treatment compared with baseline (45.9 mm³ ± 96.1 vs 156.0 mm³ ± 115.3, respectively; P = .0003). The MSTS scores (28.8 ± 1.8 after treatment vs 14.1 ± 8.6 at baseline; P < .0001) and SF-36 findings revealed a significant improvement in the quality of life after treatment compared with baseline, leaving most patients without relevant constraints. CONCLUSIONS: Combined transarterial embolization and percutaneous sclerotherapy is a minimally invasive, safe, and effective treatment option for refractory and nonresectable ABCs. Treatment fostered bone mineralization and significantly improved patients' quality of life.

Does the Duration of Primary and First Revision Surgery Influence the Probability of First and Subsequent Implant Failures after Extremity Sarcoma Resection and Megaprosthetic Reconstruction?

Complications in megaprosthetic reconstruction following sarcoma resection are quite common. While several risk factors for failure have been explored, there is a scarcity of studies investigating the effect of the duration of surgery. We performed a retrospective study of 568 sarcoma patients that underwent megaprosthetic reconstruction between 1993 and 2015. Differences in the length of surgery and implant survival were assessed with the Kaplan-Meier method, the log-rank test and multivariate Cox regressions using an optimal cut-off value determined by receiver operating curves analysis using Youden's index. 230 patients developed a first and 112 patients a subsequent prosthetic failure. The median duration of initial surgery was 210 min. Patients who developed a first failure had a longer duration of the initial surgery (225 vs. 205 min, p = 0.0001). There were no differences in the probability of infection between patients with longer and shorter duration of initial surgery (12% vs. 13% at 5 years, p = 0.492); however, the probability of mechanical failure was higher in patients with longer initial surgery (38% vs. 23% at 5 years, p = 0.006). The median length of revision surgery for the first megaprosthetic failure was 101 min. Patients who underwent first revision for infection and did not develop a second failure had a longer median duration of the first revision surgery (150 min vs. 120 min, p = 0.016). A shorter length of the initial surgery appears beneficial, however, the notion that longer operating time increases the risk of deep infection could not be reproduced in our study. In revision surgery for infection, a longer operating time, possibly indicating a more thorough debridement, appears to be associated with a lower risk for subsequent revision.

The change in plasma D-dimer does not help to guide the timing of reimplantation in two stage exchange for periprosthetic joint infection.

D-dimer has been included in the criteria by the Musculoskeletal Infection Society in 2018 as a novel parameter to diagnose prosthetic joint infection (PJI). However, it is unclear how D-dimer levels change in between stages of a two-stage exchange. We prospectively investigated 30 patients who underwent a two-stage exchange using a spacer for PJI. D-Dimer, CRP and IL-6 were collected before first and second stage surgery and the difference (Δ) in between stages was calculated. The levels of plasma D-Dimer did not change from first to second stage surgery (2770 ng/ml (IQR, 1600-3770 ng/ml) versus 2340 ng/ml (IQR, 1270-4100 ng/ml); p = 0.8) while CRP (4.0 mg/dl (IQR, 1.7-5.5 mg/dl) versus 0.6 mg/dl (IQR, 0.5-0.8 mg/dl); p < 0.001) and IL-6 (21 pg/ml (IQR, 10-29 pg/ml) versus 6 pg/ml (4-9 pg/ml); p < 0.001) decreased. The ΔD-dimer between both stages was 300 ng/ml (range: - 2820 to 4280 ng/ml), the median ΔCRP was - 3.4 mg/dl (IQR, - 1.2 to - 4.8 mg/dl) and ΔIL-6 was - 13 pg/ml (IQR, - 4 to - 20 pg/ml). In 15 of 30 cases (50%) the D-dimer level increased between both stages, whereas the level of CRP (93%; 28/30) and IL-6 (96%; 28/29) decreased in most patients. As the level of serum D-dimers varies greatly, lacks a uniform decrease and does not identify persisting infection, surgeons should be cautious when using it at the timing of reimplantation.

What Is the Implant Survivorship and Functional Outcome After Total Humeral Replacement in Patients with Primary Bone Tumors?

BACKGROUND: Total humeral replacement is an option to reconstruct massive bone defects after resection of locally advanced bone tumors of the humerus. However, implant survivorship, potential risk factors for implant revision surgery, and functional results of total humeral replacement are poorly elucidated because of the rarity of the procedure. QUESTIONS/PURPOSES: We asked: (1) What is the revision-free implant and overall limb survivorship after total humerus replacement? (2) What factors are associated with implant revision surgery? (3) What is the functional outcome of the procedure as determined by the Musculoskeletal Tumor Society (MSTS) score and the American Shoulder and Elbow Surgeons (ASES) score? METHODS: Between August 1999 and December 2018, 666 patients underwent megaprosthetic reconstruction after resection of a primary malignant or locally aggressive/rarely metastasizing tumor of the long bones at our department. In all, 23% (154) of these patients had a primary tumor located in the humerus. During the study, we performed total humeral replacement in all patients with a locally advanced sarcoma, in patients with pathological fractures, in patients with skip metastases, or in patients with previous intralesional contaminating surgery, who would have no sufficient bone stock for a stable implant fixation for a single joint megaprosthetic replacement of the proximal or distal humerus. We performed no biological reconstructions or reconstructions with allograft-prosthetic composites. As a result, 5% (33 of 666) of patients underwent total humerus replacement. Six percent (2 of 33) of patients were excluded because they received a custom-made, three-dimensionally (3-D) printed hemiprosthesis, leaving 5% (31) of the initial 666 patients for inclusion in our retrospective analysis. Of these, 6% (2 of 31) had surgery more than 5 years ago, but they had not been seen in the last 5 years. Median (interquartile range) age at the time of surgery was 15 years (14 to 25 years), and indications for total humeral replacement were primary malignant bone tumors (n = 30) and a recurring, rarely metastasizing bone tumor (n = 1). All megaprosthetic reconstructions were performed with a single modular system. The implanted prostheses were silver-coated beginning in 2006, and beginning in 2010, a reverse proximal humerus component was used when appropriate. We analyzed endoprosthetic complications descriptively and assessed the functional outcome of all surviving patients who did not undergo secondary amputation using the 1993 MSTS score and the ASES score. The median (IQR) follow-up in all survivors was 75 months (50 to 122 months), with a minimum follow-up period of 25 months. We evaluated the following factors for possible association with implant revision surgery: age, BMI, reconstruction length, duration of surgery, extraarticular resection, pathological fracture, previous intralesional surgery, (neo-)adjuvant radio- and chemotherapy, and metastatic disease. RESULTS: The revision-free implant survivorship at 1 year was 77% (95% confidence interval 58% to 89%) and 74% (95% CI 55% to 86%) at 5 years. The overall limb survivorship was 93% (95% CI 75% to 98%) after 1 and after 5 years. We found revision-free survivorship to be lower in patients with extraarticular shoulder resection compared with intraarticular resections (50% [95% CI 21% to 74%] versus 89% [95% CI 64% to 97%]) after 5 years (subhazard ratios for extraarticular resections 4.4 [95% CI 1.2 to 16.5]; p = 0.03). With the number of patients available for our analysis, we could not detect a difference in revision-free survivorship at 5 years between patients who underwent postoperative radiotherapy (40% [95% CI 5% to 75%]) and patients who did not (81% [95% CI 60% to 92%]; p = 0.09). The median (IQR) MSTS score in 9 of 13 surviving patients after a median follow-up of 75 months (51 to 148 months) was 87% (67% to 92%), and the median ASES score was 83 (63 to 89) of 100 points, with higher scores representing better function. CONCLUSION: Total humeral replacement after resection of locally advanced bone tumors appears to be associated with a good functional outcome in patients who do not die of their tumors, which in our study was approximately one- third of those who were treated with a resection and total humerus prosthesis. However, the probability of early prosthetic revision surgery is high, especially in patients undergoing extraarticular resections, who should be counseled accordingly. Still, our results suggest that if the prosthesis survives the first year, further risk for revision appears to be low. Future studies should reexamine the effect of postoperative radiotherapy on implant survival in a larger cohort and evaluate whether the use of soft tissue coverage with plastic reconstructive surgery might decrease the risk of early revisions, especially in patients undergoing extraarticular resections. LEVEL OF EVIDENCE: Level III, therapeutic study.