High prevalence of increased posterior tibial slope in ACL revision surgery demands a patient-specific approach.

PURPOSE: To determine the prevalence of an "increased posterior tibial slope (PTS)" (PTS ≥ 12°) in a population with one, two or ≥ three anterior cruciate ligament (ACL) graft insufficiencies. Furthermore, to investigate whether the prevalence of an increased PTS and the absolute PTS increases with an increasing number of ACL graft insufficiencies, as well as to determine the survival time of the first ACL graft. METHODS: Patients diagnosed with an ACL graft insufficiency between January 2021 and March 2022 were included. The PTS was measured using the proximal anatomical tibial axis on long lateral knee radiographs. Patients were divided into 3 groups depending on the number of ACL graft insufficiencies: group A (1 graft insufficiency), group B (2 graft insufficiencies) and group C (≥ 3 graft insufficiencies). The prevalence of increased PTS and absolute PTS between groups was compared alongside the survival of the first ACL graft between patients with or without increased PTS. RESULTS: Two-hundred and six patients (147 males/59 females) met the inclusion criteria. 73 patients showed an increased PTS [prevalence 35% [95% confidence interval (CI) (29%; 42%)]. 155 patients were found in category A, 42 patients in B and 9 patients in C. The prevalence of increased PTS for group A, B and C was, 32% [95% CI (25%; 40%)], 38% [95% CI (23%; 53%)] and 78% [95% CI (51%; 100%)], respectively. The prevalence of increased PTS and mean PTS did not increase significantly between group A and B. However, both parameters increased significantly between group A and C, and group B and C (p < 0.05). The survival time of the first ACL graft in patients with or without an increased PTS was 3 (interquartile range (IQR) 5) and 6 years (IQR 9), respectively (p < 0.05). CONCLUSION: There is a 35% prevalence of increased PTS in the studied ACL graft insufficient patient cohort. The survival of the first ACL graft is shorter in patients with an increased PTS. Surgeons should be aware of the high prevalence of increased PTS when consulting patients for revision ACL reconstruction as it is an important risk factor for recurrent instability.

Prior high tibial osteotomy is not a contraindication for medial unicompartmental knee arthroplasty.

PURPOSE: To report on the outcome and complications of minimal invasive medial unicondylar knee arthroplasty (UKA) after failed prior high tibial osteotomy (HTO) as treatment for medial osteoarthritis in the knee. The hypothesis was that good results can be achieved, if no excessive postoperative valgus alignment and abnormal proximal tibial geometry is present. METHODS: All medial UKAs after failed prior HTO (n = 30), performed between 2010 and 2018 were retrospectively reviewed. The patients were followed for revision surgery and survival of the UKA (defined as revision to TKA). Clinical examination using the Knee Society Score (KSS), Oxford Knee Score (OKS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), as well as radiological examination was performed. Radiographs were studied and the influence of the demographic factors and the radiographic measurements on the survival and the clinical outcome was analysed. RESULTS: After a follow-up of 4.3 ± 2.6 years (2.1-9.9) 27 UKAs were available. The survival rate was 93.0%. Two UKAs were revised to TKA (excessive valgus alignment and tibial loosening with femoropatellar degeneration). Two further patients had revision surgery (hematoma and lateral meniscus tear). Follow-up clinical and radiological examination was performed in 21 cases: KSS 82.9 ± 10.1 (54.0-100.0), KSS (function) 93.3 ± 9.7 (70.0-100.0); OKS 42.7 ± 6.0 (25.0-48.0); WOMAC 7.9 ± 15.6 (0.0-67.1). No significant influence of demographic factors or radiological measurements on the clinical outcome was present. CONCLUSION: Prior HTO is not a contraindication for medial UKA, because good-to-excellent results can be achieved in selected patients with medial osteoarthritis and previous HTO, treated with medial UKA, in a midterm follow-up. Excessive mechanical valgus axis should be avoided; therefore, patient selection and accurate evaluation of medial laxity, preoperative mechanical axis, joint line convergence and proximal tibial geometry are important. LEVEL OF EVIDENCE: III.

Antibiotic therapy alone does not have a high success rate in cases of unexpected positive cultures in intraoperative samples from hip and knee prosthesis revision.

BACKGROUND: Unexpectedly positive bacterial cultures during prosthesis revision surgery still occur on occasion despite good preoperative diagnostics. In such cases a six-week antibiotic therapy without further surgical intervention is recommended. The aim of this study was to find out how successful this procedure is. METHODS: In a study of 508 patients, who required revision surgery of total hip (THA, n = 231) or knee arthroplasties (TKA, n = 277) because of component loosening, biopsy was carried out before their surgery. The collected tissue samples (5) from the biopsy and the revision surgery procedure itself were analyzed according the criteria of the International Consensus Meeting (ICM). Tests revealed 11 patients (7 THA, 4 TKA) with unexpectedly positive bacterial cultures from tissue samples obtained during the revision surgery due to false negative preoperative diagnostic results. These 11 patients were treated with 6 weeks antibiotic therapy and examined with a follow-up of at least 2 years (42.2 ± 16.5 months). RESULTS: Five patients (2 TKA, 3 THA) became reinfected, resulting in a success rate of 54.5%. CONCLUSION: Antibiotic therapy alone of an unexpected positive intraoperative bacterial culture in prosthesis revision surgery seems to be less successful than previously assumed.

Soaking of autografts in vancomycin is highly effective in preventing postoperative septic arthritis after revision anterior cruciate ligament reconstruction.

PURPOSE: To determine and compare the incidence of postoperative septic arthritis following revision anterior cruciate ligament reconstruction (R-ACLR) with and without soaking of the graft in vancomycin solution prior to implantation in a large single-centre series. METHODS: A total of 2155 isolated R-ACLR with autologous tendons were performed from 2004 to 2019 and were reviewed with regard to the occurrence of postoperative septic arthritis. From February 2017 onwards, all grafts were wrapped in a vancomycin-soaked (5 mg/ml) gauze swab between harvest and implantation (517 patients, treatment group (2), prospectively followed). These were compared to 1638 patients before that date (control group (1), retrospectively evaluated). The technique of R-ACLR did not significantly change during the years of the study. Hamstring tendons were used in 1310 patients (60.8%) and quadriceps tendons with patellar bone block were used in 845 patients (39.2%), respectively, with no difference between the groups (n.s.). Routine follow-up examination was performed 6 weeks postoperatively (follow-up rate 96.5%), and patients with no treatment for septic arthritis until that time were classified as non-infected. RESULTS: There were 14 cases of postoperative septic arthritis in group 1 (incidence 0.9%), and none in group 2 (incidence 0.0%), respectively. The difference was significant (p = 0.029). CONCLUSION: Soaking of the graft in vancomycin solution prior to implantation dramatically reduces the incidence of postoperative septic arthritis in R-ACLR. LEVEL OF EVIDENCE: III.

Posterior cruciate ligament lesions are mainly present as combined lesions even in sports injuries.

PURPOSE: To analyse 1000 consecutive patients, treated with isolated or combined posterior cruciate ligament (PCL) reconstruction in a single centre according to the epidemiological factors and differences in injury patterns depending on the activity during trauma. METHODS: Between 2004 and 2019, one thousand isolated and combined PCL reconstructions were performed. The medical charts and surgical reports of all patients were analysed regarding epidemiological factors. The PCL lesions were divided into isolated and combined lesions with at least one additional ligamentous injury. The influence of activity during accident and additional injury on the presence of isolated or combined lesions and injury patterns was calculated. RESULTS: In 388 patients (38.8%), sporting activity was the main activity in PCL lesions, followed by traffic accidents in 350 patients (35.0%). Combined injuries were present in 227 patients (58.5%) with sports injuries and 251 patients (71.7%) with traffic accidents. Only during handball, an isolated PCL lesion (69.1%) was more common than a combined lesion. Highest rate of combined lesions was present in car accidents (91.7%). In all activities except skiing and biking, the most common additional peripheral injury was a tear of the posterolateral corner. In skiing and biking accidents, the most common additional peripheral lesion was a lesion of the medial collateral ligament. In patients with PCL lesion and additional fracture of the same lower extremity, a combined lesion was more common than an isolated lesion (p = 0.001). CONCLUSION: Combined PCL lesions are more common than isolated lesions, even in sports injuries (except handball). Incidence and injury pattern vary depending on activity during trauma. Main additional peripheral lesion is a lesion of the posterolateral corner, except biking and skiing accidents where a medial lesion is more common. LEVEL OF EVIDENCE: Level III.

Soaking of the graft in vancomycin dramatically reduces the incidence of postoperative septic arthritis after anterior cruciate ligament reconstruction.

PURPOSE: To determine and compare the incidence of postoperative septic arthritis following anterior cruciate ligament reconstruction (ACLR) with and without soaking of the graft in vancomycin solution prior to implantation in a large single-centre case series. METHODS: From 2004 to 2019, a total of 10,516 primary ACLR were performed and reviewed with regard to the occurrence of postoperative septic arthritis. From February 2017 onwards, all grafts were wrapped in a vancomycin-soaked (5 mg/ml) gauze swab between harvest and implantation (2294 patients, treatment group (2), prospectively followed). These were compared to 8222 patients before that date (control group (1), retrospectively evaluated). The technique of ACLR did not significantly change during the years of the study. There was no difference between the groups with regard to graft choice: Hamstring tendons were used in 99% and quadriceps tendons were used in 1% in both groups, respectively (n.s.). Routine follow-up examination was performed at 6 weeks (follow-up rate 97.1%) postoperatively. Patients with no treatment for septic arthritis at that time were classified as non-infected. RESULTS: There were 35 cases of postoperative septic arthritis in group 1 (incidence: 0.4%), and none in group 2 (incidence 0.0%), respectively. The difference was significant (p < 0.001). CONCLUSIONS: Soaking of the graft in vancomycin solution prior to implantation dramatically reduces the incidence of postoperative septic arthritis in primary ACLR and should, therefore, be used in prevention of this major complication. LEVEL OF EVIDENCE: III.

Lower incidence of post-operative septic arthritis following revision anterior cruciate ligament reconstruction with quadriceps tendon compared to hamstring tendons.

PURPOSE: To determine and compare the incidence of post-operative septic arthritis following revision anterior cruciate ligament reconstruction (R-ACLR) with autologous quadriceps tendon (with patellar bone block) compared to autologous hamstring tendons (semitendinosus and gracilis). METHODS: A total of 1638 isolated R-ACLR with either autologous hamstring tendons (n = 1004, 61.3%) or quadriceps tendon (n = 634; 38.7%) were performed between 2004 and 2017 and were retrospectively analysed with regard to the occurrence of post-operative septic arthritis. The technique of R-ACLR did not significantly change during the years of the study. All patients received pre-op i.v.antibiotics, but no presoaking of the grafts in vancomycin was performed in the years of the study. The individual decision of graft choice was based on graft availability, tunnel position and the presence of tunnel widening. Generally, hamstring tendons were preferred. There were no clinically relevant differences between the groups regarding gender or age. Routine follow-up examination was performed 6 weeks after the index operation (follow-up rate 96.5%), and patients unsuspicious for septic arthritis at that time were classified as non-infected. RESULTS: Fourteen patients with septic arthritis were identified, resulting in an overall incidence of 0.85%. There was one patient with septic arthritis in the quadriceps tendon group (incidence: 0.16%) and 13 patients in the hamstring tendons group (incidence: 1.29%), respectively. The difference was significant (p = 0.013). CONCLUSION: In this series, the incidence of post-operative septic arthritis after R-ACLR was lower when quadriceps tendon graft was used compared to hamstring tendon grafts. LEVEL OF EVIDENCE: III.

Derotational femoral osteotomy changes patella tilt, patella engagement and tibial tuberosity trochlear groove distance.

PURPOSE: The aim was to assess the influence of femoral derotational osteotomy on patella tilt (PT), axial patella engagement (AEI) and tibial tuberosity trochlear groove distance (TTTG). METHODS: Derotational femoral osteotomy was performed on ten lower limbs of body donors embalmed with alcohol-glycerine. Femoral torsion, tibial torsion, knee torsion, PT, AEI and TTTG were evaluated on axial CT slices for an absolute femoral torsion of 15°, 20°, 25°, 30°, 35° and 40°. A linear mixed model analysis was used to estimate the effect of femoral torsion on PT, AEI, TTTG and knee torsion adjusted for correlation due to repeated observations. Estimates with 95% confidence intervals were used to represent the mean change in the dependent variables for one unit of change (degree, mm or AEI) in the predictor variable. RESULTS: A significant correlation was observed between femoral torsion and AEI (p < 0.001), PT (p < 0.001) and TTTG distance (p = 0.002). In cases of increased internal femoral torsion, a significant decreased AEI (estimate - 0.003, 95% CI - 0.003 to - 0.002), an increased PT (estimate 0.3, 95% CI 0.2-0.4) and an increased TTTG distance (estimate 0.1, 95% CI 0.1-0.2) were observed. No correlation was seen between change in femoral torsion and knee torsion (n.s.). CONCLUSIONS: Derotational femoral osteotomy has a significant impact on patella tilt and axial patella engagement. Moreover, TTTG distance is slightly changed by a derotational femoral osteotomy, which has to be taken into account preoperatively when considering surgical procedures. LEVEL OF EVIDENCE: Level V.

Excellent long-term results in combined high tibial osteotomy, anterior cruciate ligament reconstruction and chondral resurfacing in patients with severe osteoarthritis and varus alignment.

PURPOSE: To determine survivorship and functional results of medial open-wedge high tibial osteotomy (HTO) combined with anterior cruciate ligament reconstruction (ACLR) and a chondral resurfacing (CR) procedure (abrasion/microfracture) in patients with Kellgren-Lawrence grade 3 and 4 osteoarthritis with full thickness-cartilage defects, ACL-insufficiency and varus alignment. METHODS: A cohort of 23 patients undergoing a combined procedure of HTO (fixation with angular stable internal fixator, Tomofix®), ACLR and CR for the treatment of severe symptomatic medial osteoarthritis, ACL insufficiency and varus alignment (> 4°) between 2005 and 2009 was prospectively surveyed with a minimum follow-up of 10 years with regard to survival (not requiring arthroplasty), functional outcome (subjective IKDC score), pain level (numeric rating scale), Oxford Knee Score (OKS) and subjective satisfaction. The Wilcoxon signed-rank-test was used for statistical evaluation of non-parametric data in these related samples. RESULTS: Twenty-one cases were included, one case with incomplete follow-up data and another case excluded. The follow-up rate was 91% at 12.0 ± 1.0 years (10.0-13.4). Mean age at time of surgery was 47.3 ± 5.9 years (37.8-57.7). At final follow-up, no arthroplasty was performed in any of the cases (survival: 100%). Subjective IKDC score improved from 47 ± 11 to 75 ± 15 at 1, 72 ± 15 at 3, 73 ± 17 at 6 years and 70 ± 16 at final follow-up (p < 0.001), respectively. At final follow-up the OKS was 40 ± 7 (17-48) and pain-level significantly decreased from 7.5 ± 1.0 preoperatively to 2.9 ± 2.3 (p < 0.001) at final follow-up. All patients were satisfied with the result and stated that they would retrospectively undergo the procedure again. CONCLUSION: A combined approach of HTO, ACLR and a CR shows excellent results in a long-term follow-up in selected young patients even in severe osteoarthritis. However, the role and potential benefit of the ACLR and CR compared to HTO alone remains unclear. LEVEL OF EVIDENCE: Therapeutic case series, Level IV.

C-reactive protein is not a screening tool for late periprosthetic joint infection.

BACKGROUND: Preoperative diagnosis of periprosthetic joint infection (PJI) is important because of the therapeutic consequences. The aim of the present study is to investigate whether the serum C-reactive protein (CRP) level can be used as a screening tool for late PJI. MATERIALS AND METHODS: A cohort of 390 patients with revision surgery of total hip prostheses (200) or total knee prostheses (190) was assessed for late PJI by determining CRP serum level and performing preoperative aspiration with cultivation and intraoperative tissue analyses with cultivation and histologic examination, using the Musculoskeletal Infection Society (MSIS) and International Consensus Meeting (ICM) criteria. RESULTS: A total of 180 joints were rated as PJI (prevalence 46%). Of these, 42.8% (77) showed a CRP level below 10 mg/L and 28.3% (51) showed a normal CRP level of less than 5 mg/L. The 76.9% of the cases with slow-growing bacteria showed a CRP level below 10 mg/L, and 61.5% showed a normal CRP level. CONCLUSIONS: Serum CRP level should not be used as a screening tool to rule out late PJI. LEVEL OF EVIDENCE: Level 2 (diagnostic study).

Arthroscopic autologous chondrocyte implantation in the knee with an in situ crosslinking matrix: minimum 4-year clinical results of 15 cases and 1 histological evaluation.

PURPOSE: To clinically evaluate an arthroscopic autologous chondrocyte implantation (ACI) technique with an in situ crosslinking matrix for the treatment of full thickness cartilage defects of the knee and to present histological results of a graft cartilage biopsy obtained after 1.5 years. METHODS: Fifteen cases of arthroscopic autologous chondrocyte implantation in the knee performed between November 2011 and October 2012 were included in the study. Medical charts and operational reports were screened and the patients were contacted after 0.8 ± 0.3 years (0.4-1.3) and 4.3 ± 0.3 years (4.0-4.8) to asses subjective IKDC and re-operation. The Tegner activity scale was collected at the second follow-up time point. Subjective IKDC response rates were assessed at both follow-up time points. RESULTS: The first and second follow-up was completed by all 15 patients (100%). The subjective IKDC scores showed a significant improvement (pre-operative 44.5 ± 15.9, first follow-up 71.1 ± 15.9, p < 0.001, second follow-up 72.6 ± 17.3, p < 0.001). The overall response rate was 66.7% (n = 10) at follow-up one and two. There were no significant differences in pre-injury (4, range 1-9) and follow-up two (4, range 2-7) Tegner activity scales (p = n.s.). Two patients required re-operation in the index knee, not related to the ACI procedure. No complication related to the ACI or the implantation technique occurred. The histological results showed excellent cartilage regeneration. CONCLUSION: Arthroscopic ACI using an in situ crosslinking matrix is a safe and reliable treatment option for full-thickness cartilage defects of the knee.

Septic arthritis after arthroscopic posterior cruciate ligament and multi-ligament reconstructions is rare and can be successfully treated with arthroscopic irrigation and debridement: analysis of 866 reconstructions.

PURPOSE: The purpose of this study was to determine the incidence of septic arthritis following arthroscopic posterior cruciate ligament (PCL) and multi-ligament reconstructions, and to evaluate a treatment regime with sequential arthroscopic irrigation and debridement procedures combined with antibiotic therapy that is focused on retention of the graft. METHODS: Between 2004 and 2016 a total of 866 PCL reconstructions and multi-ligament reconstructions were performed at our institution (408 isolated PCL reconstructions, 458 combined reconstructions). Medical charts of all cases were retrospectively reviewed with regard to the occurrence of septic complications. These cases were analysed with special focus on clinical management, number of reoperations and if the grafts were retained. Further, microbiological findings, postoperative clinical course and available clinical outcome data were evaluated. RESULTS: Four cases of septic arthritis (0.5%) were identified (follow-up rate 96.5%): two following isolated PCL reconstruction (0.5%), and two following multi-ligament reconstruction (0.4%), respectively. Septic arthritis was successfully treated in all cases with a mean of 2.5 ± 2.4 irrigation and debridement procedures (1-6). In one case of isolated PCL reconstruction, the graft was resected within the fifth irrigation and debridement due to septic loosing of the femoral fixation. All other grafts were retained. With regard to the outcome, all patients were subjectively satisfied with good stability (stress radiographs) in cases of retained grafts. CONCLUSION: Postoperative septic arthritis after arthroscopic PCL and complex knee ligament reconstructions is a rare but serious complication. Arthroscopic graft-retaining treatment is recommended, as it is established in ACL surgery. Graft retention can be expected in the majority of the cases. LEVEL OF EVIDENCE: Case series, Level 4.

Meniscus repairs can be saved in the event of postoperative septic arthritis.

PURPOSE: No systematic studies on optimal treatment of postoperative septic arthritis following arthroscopic meniscus repair are available. The purpose of this study was to retrospectively evaluate the fate of repaired menisci in cases of postoperative septic arthritis, with treatment for infection focused on arthroscopic irrigation and debridement (I&D) and intention to maintain the meniscus. METHODS: Data of two sports orthopedics centers of the last 10 years were pooled (approximately 25,000 arthroscopic procedures of the knee). All cases of septic arthritis following arthroscopic meniscus repair were identified. These cases were retrospectively evaluated with regard to clinical course and management, especially the number of necessary I&Ds, if eradication was achieved, and if the repaired meniscus was retained or a partial resection was necessary ('early failure'). Patients with initially maintained meniscus repairs were contacted if further meniscus surgery was performed in further follow-up ('late failure'). RESULTS: 20 patients with 23 repaired menisci were included. In 65% (13 cases), a concomitant anterior cruciate ligament reconstruction was performed. A mean of 2.0 ± 1.0 (1-4) arthroscopic I&Ds were performed in the treatment of septic arthritis. In two cases, additional open surgery was performed (after outside-in sutures). Eradication was achieved in all cases. Four repaired menisci (17.4%) showed loosened fixation or substantial degradation and were consequently partially resected within treatment for septic arthritis (early failures). The follow-up rate for the 19 initially maintained menisci was 94.7% after 3.0 ± 2.2 years (median 2.8, 0.4-7.8). Three of these underwent further partial resection (13.0%). Cumulative 3-year survival rate (Kaplan-Meier method) of all repairs was 70.7% (95% CI 50.3-91.1%), and for the subgroup of initially maintained menisci 85.6% (95% CI 67.0-100.0%), respectively. CONCLUSION: Septic arthritis following meniscus repair can be successfully treated with (sequential) arthroscopic I&Ds. There is a considerable rate of early failures, however, in a mid-term follow-up the failure rate of initially retained menisci is low and comparable to what we know from the literature for cases without infection. Therefore, it is generally recommended to try to save the repaired menisci in these cases. LEVEL OF EVIDENCE: IV, therapeutic case series.

Treatment of tibial nonunion with bone defect using a heterotopic ossification as autologous bone graft: literature overview and case report.

INTRODUCTION: Nonunion after open fracture of the lower leg is a frequent complication with a prevalence of up to 40%. In cases with major bone defects, revision of the osteosynthesis with bone grafting is commonly performed. Until today, there is no report on treatment of a tibial nonunion with transplantation of a heterotopic ossification. PRESENTATION OF CASE: We present a case of a 27-year-old male patient, who suffered from a paragliding accident with major injuries. An open fracture of the lower leg (Gustilo-Anderson IIIB) was initially treated with external fixation and vacuum-assisted closure, followed by reamed intramedullary nailing. The tibia resulted in a bone defect situation with nonunion. It was successfully treated with revision, fibular osteotomy and transplantation of a heterotopic ossification, harvested from the ipsilateral hip. CONCLUSION: In special cases, autologous transplantation of a mature heterotopic ossification is an attractive bone graft option in treating nonunion defects.

Single-stage Acetabular Revision During Two-stage THA Revision for Infection is Effective in Selected Patients.

BACKGROUND: The treatment of periprosthetic infections of hip arthroplasties typically involves use of either a single- or two-stage (with implantation of a temporary spacer) revision surgery. In patients with severe acetabular bone deficiencies, either already present or after component removal, spacers cannot be safely implanted. In such hips where it is impossible to use spacers and yet a two-stage revision of the prosthetic stem is recommended, we have combined a two-stage revision of the stem with a single revision of the cup. To our knowledge, this approach has not been reported before. QUESTIONS/PURPOSES: (1) What proportion of patients treated with single-stage acetabular reconstruction as part of a two-stage revision for an infected THA remain free from infection at 2 or more years? (2) What are the Harris hip scores after the first stage and at 2 years or more after the definitive reimplantation? METHODS: Between June 2009 and June 2014, we treated all patients undergoing surgical treatment for an infected THA using a single-stage acetabular revision as part of a two-stage THA exchange if the acetabular defect classification was Paprosky Types 2B, 2C, 3A, 3B, or pelvic discontinuity and a two-stage procedure was preferred for the femur. The procedure included removal of all components, joint débridement, definitive acetabular reconstruction (with a cage to bridge the defect, and a cemented socket), and a temporary cemented femoral component at the first stage; the second stage consisted of repeat joint and femoral débridement and exchange of the femoral component to a cementless device. During the period noted, 35 patients met those definitions and were treated with this approach. No patients were lost to followup before 2 years; mean followup was 42 months (range, 24-84 months). The clinical evaluation was performed with the Harris hip scores and resolution of infection was assessed by the absence of clinical signs of infection and a C-reactive protein level less than 10 mg/L. All patients were assessed before surgery, between stages, every 3 months during the first year after surgery, every 6 months during the second year postoperative, and at latest followup, and were retrospectively drawn from a longitudinally maintained institutional database. RESULTS: Thirty-four of 35 patients (97.2%; 95% CI, 85.4%-99.5%) appeared free of infection by criteria of Masri et al. and Zimmerli et al. at latest followup. The Harris hip score was 61 ± 13 points after the first operation and 82 ± 16 points 2 years after the second operation. CONCLUSIONS: This technique is a promising treatment option for periprosthetic infections of the hip in which substantial acetabular defects exclude implantation of a normal spacer and a two-stage revision of the femoral component is favored. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Traumatic graft rupture after primary and revision anterior cruciate ligament reconstruction: retrospective analysis of incidence and risk factors in 2915 cases.

PURPOSE: To determine incidence and risk factors for traumatic graft rupture following primary and revision anterior cruciate ligament (ACL) reconstruction. METHODS: All cases of isolated ACL reconstructions (primary or revision) performed at our institution between January 2007 and December 2010 were included. From this group of 2467 primary reconstructions (32.4 ± 12.2 years) and 448 revision reconstructions (33.0 ± 10.4 years), we identified all patients who underwent revision ACL reconstruction following traumatic graft rupture in further course and all patients who underwent contralateral primary ACL reconstruction until January 2014. Age, gender, time from index procedure and graft diameter (for hamstring autografts) were analysed in terms of being a potential risk factor for graft rupture. RESULTS: Within a follow-up period of 5.0 ± 1.1 years (3.0-7.0), a total of 82 traumatic graft ruptures were identified, resulting in an incidence of 2.8 %. Seventy-three cases were seen following primary reconstructions (3.0 %), and nine cases following revision reconstructions (2.0 %), respectively (n.s.). Age younger than 25 years was identified as a risk factor for both groups (p = 0.001 and p = 0.008; odds ratio 6.0 and 6.4, respectively). In primary reconstruction, male patients had a higher risk of graft rupture compared with females (3.7 vs. 1.6 %; p = 0.005), and the first year after index procedure was associated with a higher risk of graft rupture compared with the following (p < 0.001). Graft diameter did not influence the risk of graft rupture. Incidence of contralateral ACL rupture was 3.1 %, which was not different to the incidence of graft rupture ipsilaterally (n.s.). CONCLUSION: No statistically significant differences were seen between graft rupture incidence of primary and revision ACL reconstructions. Young age (<25 years) and short time to the index procedure (especially within the first year) were confirmed as risk factors for graft rupture in both groups. Male gender was a risk factor for primary reconstructions. Graft diameter had no influence on graft rupture rates. No difference in incidence of graft rupture compared to ACL rupture on the contralateral side was apparent. LEVEL OF EVIDENCE: Retrospective case series, Level IV.

Open-Wedge High Tibial Osteotomy and Combined Abrasion/Microfracture in Severe Medial Osteoarthritis and Varus Malalignment: 5-Year Results and Arthroscopic Findings After 2 Years.

PURPOSE: To determine survivorship and functional results of medial open-wedge high tibial osteotomy (HTO) combined with a chondral resurfacing procedure (abrasion/microfracture) in patients with Kellgren-Lawrence grade 3 and 4 osteoarthritis with full-thickness cartilage defects and varus malalignment. METHODS: From September 2005 to December 2008, all cases of HTO (fixation with an angular-stable internal fixator) combined with a chondral resurfacing procedure performed at our institution were prospectively surveyed, with a minimum follow-up of 5 years, regarding survival (not requiring arthroplasty), functional outcome (subjective International Knee Documentation Committee [IKDC] score), and subjective satisfaction (whether patients would undergo the operation again). Clinical evaluation (according to objective IKDC parameters), radiologic evaluation, and revision arthroscopy for evaluation of regenerated cartilage were performed between 1 and 2 years. RESULTS: A total of 91 knees (85 patients; mean age, 50.4 ± 8.0 years; age range, 28.3 to 67.7 years) were included. The survival rate was 95.2% (95% confidence interval, 90.7% to 99.7%) at 5 years, with 4 conversions to arthroplasty (3 unicondylar and 1 total knee arthroplasty; follow-up rate, 87.9%). Subjective IKDC scores significantly improved from 45.1 ± 11.6 points preoperatively to 69.1 ± 14.2 points after 1 year, 66.4 ± 14.5 points after 3 years, and 67.2 ± 14.4 points after 5 years (P < .001). In 94.9% of the cases patients were satisfied with the result after 5 years, including those with arthroplasty. Revision arthroscopy was performed in 80 cases (87.9%) at 1.5 ± 0.8 years: Cartilage regeneration was graded good in 50.0% and excellent in 25.8% on the tibial side compared with 48.1% and 39.0%, respectively, on the femoral side (P < .001). The overall complication rate was 6.6%. CONCLUSIONS: HTO in combination with a chondral resurfacing procedure is effective in the treatment of severe medial osteoarthritis and varus malalignment. The effect of the chondral resurfacing in this combined approach remains unclear. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Short-term results of tibial interference screw fixation for transtibial medial meniscus posterior root pull-out repair.

Background: To evaluate the technique of transtibial pull-out repair with tibial interference screw fixation for medial meniscus posterior root (MMPR) tear by reporting on short-term outcomes and complications. Methods: All MMPR repairs performed between January 2019 and August 2021 (n = 70) were retrospectively screened regarding demographic data and surgical parameters. The patients were questioned for performed revision surgery, symptoms and complications. The Numeric Rating Scale (NRS) for pain, Lysholm Knee Score and International Knee Documentation Committee Subjective Knee Form (IKDC) questionnaires were used to evaluate clinical outcome. In cases of revision surgery for re-tear the mode of failure was intraoperatively classified (patients with re-tear were excluded from the clinical follow-up examination). The influence of demographic and treatment parameters (surgical and rehabilitation) on the incidence and mode of re-tear and clinical scores was evaluated. Results: After 2.3 ± 0.7 years, 62 patients (88.6 %) were available for follow-up. There were no direct intra- or postoperative complications. No revision was performed due to symptoms related to the tibial fixation material. The mean surgery time was 33.5 ± 10.8 min. The overall re-tear rate was 17.7 % (11 patients) of whom 10 were treated surgically and one conservatively. Primary mode of failure was suture cut-out from the meniscus (70 %). The NRS, Lysholm Knee Score and subjective IKDC were obtained in 38 patients and improved from 6.8 ± 2.4, 40.1 ± 23.9 and 32.8 ± 16.3 to 2.2 ± 2.2, 80.5 ± 16.3 and 63.0 ± 13.9, respectively (all p < 0.001). No influence was observed from demographic and treatment parameters on re-tear rates or clinical Scores. Conclusions: Tibial interference screw fixation is a fast and promising technique for MMPR transtibial pull-out repair. In the presented technique, utilizing non-absorbable locking sutures alongside tibial interfenrence screw fixation, the primary mode of failure was suture cut-out from the meniscus.

Effect of Anterior Tibial Closing Wedge Osteotomy on Coronal Tibial Alignment in Relation to Preoperative Medial Proximal Tibial Angle and Wedge Height.

BACKGROUND: The posterior tibial slope has been identified as an anatomic risk factor for anterior cruciate ligament insufficiency and reruptures after anterior cruciate ligament reconstruction. Anterior tibial closing wedge osteotomy for correction of sagittal plane deformities has the potential to cause an unintended change in coronal plane alignment. PURPOSE: To evaluate the effects of anterior tibial closing wedge osteotomies for correction of posterior tibial slope on coronal plane alignment using an infratuberosity surgical approach and to identify predictive factors for a change in medial proximal tibial angle (MPTA). STUDY DESIGN: Case series; Level of evidence, 4. METHODS: This study reports on retrospectively obtained data from radiographic measurements of 38 anterior tibial closing wedge osteotomies. All patients underwent revision anterior cruciate ligament reconstruction and had undergone ≥1 previous anterior cruciate ligament reconstruction. In all patients, an infratuberosity approach was used with angular stable plate fixation. Pre- and postoperative radiographs were examined retrospectively to detect changes in the sagittal and coronal plane alignment (posterior tibial slope and MPTA). A multivariate regression analysis was used to identify predictors for a change in MPTA. RESULTS: The study group consisted of 14 women and 24 men whose mean ± SD age at the index procedure was 31.6 ± 8.7 years (range, 17-51 years). Posterior tibial slope decreased significantly (by 7.2° ± 2.3°; P < .001) from 14.6° ± 2.0° preoperatively to 7.4° ± 2.1° postoperatively. MPTA decreased significantly by 1.3° ± 1.5° (P = .005) from pre- to postoperative measurement. Mean wedge height was 9.3 ± 1.1 mm. A lower preoperative MPTA (coefficient = 0.32; P = .017; 95% CI, 0.06-0.59) and larger wedge height (coefficient = 0.48; P = .029; 95% CI, 0.05-0.9) were significant predictive factors for a decrease in MPTA. CONCLUSION: Anterior tibial closing wedge osteotomy for posterior tibial slope reduction resulted in a slight but significant decrease of the MPTA in the coronal plane. These changes were dependent on the preoperative MPTA and the wedge height.

The Patellar Instability Probability Calculator: A Multivariate-Based Model to Predict the Individual Risk of Recurrent Lateral Patellar Dislocation.

BACKGROUND: Predicting the risk of recurrence is of great interest when counseling patients after primary lateral patellar dislocation (LPD). PURPOSE: To investigate a multivariate model to predict the individual risk of recurrent LPD. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: The study population included patients with primary LPD, knee imaging, and a minimum 2-year follow-up after nonoperative treatment. Data including patient characteristics and anatomic patellar instability risk factors were collected retrospectively from 7 national study centers. Bivariate and multivariate regression analyses were carried out to identify risk factors for recurrent LPD and to generate an accuracy-optimized model for out-of-sample prediction. RESULTS: In total, 115 of 201 patients (57%) experienced recurrent LPD within 2 years after primary LPD. Age ≤16 years at primary LPD (odds ratio [OR], 5.0), history of contralateral instability (OR, 2.4), and trochlear dysplasia (Dejour type B-D: OR, 2.5; lateral trochlear inclination ≤12°: OR, 2.7) were significant risk factors for recurrent LPD (P < .05). The prediction accuracy including these 3 risk factors was 79%. Patella alta, an increased tibial tubercle to trochlear groove distance, and patellar tilt had neither an association with increased recurrence rates nor an influence on prediction accuracy of recurrent LPD. CONCLUSION: Young age and trochlear dysplasia are major risk factors for early recurrent LPD. A multivariate model including age at primary LPD, lateral trochlear inclination, and history of contralateral LPD achieved the highest prediction accuracy. Based on these findings, the patellar instability probability calculator is proposed to estimate the individual risk of early recurrence when counseling patients after primary LPD.