Meniscal Repair Outcome in 3829 Patients With a Minimum Follow-up From 2 Years Up to 5 Years: A Meta-analysis on the Overall Failure Rate and Factors Influencing Failure.

BACKGROUND: The importance of meniscal repair is widely accepted because of the association of loss of meniscal tissue with the development of early-onset knee arthritis. Many factors influencing the results of meniscal repair have been reported, but results remain controversial. PURPOSE: This meta-analysis determines the pooled meniscal repair failure rate of studies with a minimum follow-up of 2 years up to 5 years, with a mean follow-up of 43 months. Moreover, selected failure-influencing factors are analyzed. STUDY DESIGN: Systematic review and meta-analysis; Level of evidence, 4. METHODS: PubMed and Scopus were searched for studies published between January 2000 and November 2021 reporting on meniscal repair outcome with a minimum follow-up of 24 months. The overall pooled failure rate and pooled failure rates for possible predictors were calculated. Random-effect models were used to pool failure rates, and effect estimates in the form of odds ratios with 95% CIs were established. RESULTS: The initial literature search identified 6519 studies. A total of 51 studies met the inclusion criteria. In total, 3931 menisci were included with an overall failure rate of 14.8%. Subgroup analysis revealed a significantly lower failure rate for meniscal repair with concomitant anterior cruciate ligament (ACL) reconstruction compared with knees without any reported injury to the ACL (8.5% vs 14%; P = .043). The pooled failure rate for lateral meniscal repair was significantly lower than that for medial meniscal repair (6.1% vs 10.8%; P = .031). Pooled failure rates of all-inside and inside-out repair were not significantly different (11.9% vs 10.6%; P > .05). CONCLUSION: This meta-analysis on close to 4000 patients demonstrates an overall meniscal repair failure rate of 14.8% at a minimum follow-up from 2 years up to 5 years. Meniscal repair remains a procedure with a high failure rate, especially within the first 2 postoperative years. This review and meta-analysis also identified clinically relevant factors associated with favorable outcomes such as concomitant ACL reconstruction or repair of the lateral meniscus. All-inside meniscal repair with the latest-generation devices yields failure rates of <10%. The failure mechanism and the time of failure is poorly documented; further studies are needed for a better understanding of the retear mechanism.

Biomechanical Comparison of Anterior Cruciate Ligament Reconstruction Using a Single-Bundle Round or Ribbon-like Hamstring Tendon Graft.

BACKGROUND: Persistent instability of the knee is reported in up to 30% of patients after anterior cruciate ligament (ACL) reconstruction. Based on anatomic findings showing that ACL is a flat ribbon-like structure that twists during knee flexion, a new surgical ACL reconstruction technique using a ribbon-like graft has been developed. However the effect of this surgical technique on knee kinematics has not yet been evaluated. PURPOSE: To compare the anteroposterior and rotational stability of the knee after ACL reconstruction using single-bundle (SB) round and ribbon-like grafts in anterolateral-intact/deficient knees. STUDY DESIGN: Controlled laboratory study. METHODS: Twelve human fresh-frozen cadaveric knees were tested with a 6 degrees of freedom robotic system. Internal rotation and anterior translation of the knee were recorded from 0° to 90° of flexion. A full kinematic assessment was performed in each of the following conditions: (1) intact knee, (2) after sectioning of the ACL, (3) after ACL reconstruction using a SB hamstring tendon graft in a round configuration and a ribbon-like configuration, and (4) after sectioning of the anterolateral structures. One-way analysis of variance and post hoc Tukey tests were used for statistical analyses. RESULTS: When compared with the intact knee, the ACL-deficient knee demonstrated a mean ± SD increase in anterior translation and internal rotation of 6.3 ± 2.5 mm (P < .01) and 5.8°± 2.3° (P < .01), respectively. After ACL reconstruction using a SB ribbon-like graft, the mean difference in anterior translation and internal rotation as compared with the intact knee was -0.1 ± 1.5 mm (P = .842) and 0.0°± 1.1° (P = .999). These differences from the intact knee were also not significant after ACL reconstruction using a round graft (-0.1 ± 1.3 mm, P = .999; -0.5°± 1.5°, P = .401). In the ACL-reconstructed knee using either a ribbon-like or round graft, sectioning of the anterolateral structures did not induce a significant increase of anterior translation and internal rotation of the knee. CONCLUSION: ACL reconstruction using a SB ribbon-like or round graft restored the kinematics of the intact knee at time zero. Secondary sectioning of the anterolateral structures in the ACL-reconstructed knee using both types of graft did not significantly affect the anterior translation and internal rotation of the knee. CLINICAL RELEVANCE: This is the first biomechanical study on the new ACL reconstruction technique using a ribbon-like graft.

Joint fluid concentrations of amphotericin B after local application with calcium sulphate-report of 2 cases.

Fungal periprosthetic joint infections (PJI) are difficult to treat, due to important biofilm formation and limited local penetration of systemically administered antifungals. Calcium sulphate (CaSO4 ) might be a promising carrier to increase local concentration of antifungals. We hypothesized that local amphotericin B release from CaSO4 is high enough to significantly contribute to treatment of fungal PJI. We report joint fluid and serum concentrations of amphotericin B after local application with CaSO4 as an implanted resorbable carrier material as adjunct to standard surgical and systemic antifungal treatment in two cases of PJI with Candida spp. Maximal joint fluid amphotericin B concentration was 14.01 mg/L 5 days after the second local administration of liposomal amphotericin in Case One and 25.77 mg/L 14 days after the second local administration in Case Two. Concentrations higher than minimal inhibitory concentrations (MIC) could be measured for 21 days and 17 days after local administration in Case One and Two, respectively. In Case Two, serum concentration of amphotericin B was <0.01 mg/L 3 days after local administration of 450 mg liposomal amphotericin B. No local or systemic adverse reaction was observed. Fungal PJI was successfully eradicated in both cases with a follow-up of 12 months in Case One and 20 months in Case Two. Application of amphotericin B-loaded CaSO4 was associated with joint fluid concentrations higher than minimal inhibitory concentrations for Candida spp. for approximately 3 weeks, with the advantage that the carrier material dissolves spontaneously and does not require secondary removal. Relapse of fungal infections did not occur in these two patients.

[Unicompartmental knee arthroplasty - a solution?] / Teilprothesen am Kniegelenk ­ wann sinnvoll?

Unicompartmental knee arthroplasty - a solution? Abstract. Unicompartmental knee arthroplasty (UKA) has various advantages over total knee arthroplasty (TKA); however, national joint registries communicate a significantly higher revision rate. Nevertheless, good results with high patient satisfaction can be achieved by appropriate patient selection. The good functional outcome may be due to the philosophy of the procedure, since the unicompartmental joint replacement is a pure resurfacing replacement, which aims to restore the individual, variable native, pre-arthrotic alignment, joint line and knee laxity, thus respecting the kinematics of the native knee joint. In addition, important proprioceptive structures such as ligaments are preserved. The advantages of unicompartmental joint replacement (minimally invasive procedure, preserving ligaments, cartilage and bone stock, more physiological kinematics, faster rehabilitation and easier revision surgery) outweigh the disadvantages of this procedure (technically more demanding, higher revision rate in national registers).

Anterolateral Ligament Reconstruction and Modified Lemaire Lateral Extra-Articular Tenodesis Similarly Improve Knee Stability After Anterior Cruciate Ligament Reconstruction: A Biomechanical Study.

PURPOSE: To determine the stabilizing role of anterolateral ligament reconstruction (ALLR) and modified Lemaire lateral extra-articular tenodesis (LET) performed in combination with anterior cruciate ligament reconstruction (ACLR) and to determine whether either procedure was superior to the other. METHODS: Six nonpaired, human, fresh-frozen cadaveric knees were tested with a 6-df robotic system. Internal rotation and anterior translation of the knee were recorded from 0° to 90° of flexion after application of a 5-Nm internal rotation torque and a 134-N anterior load, respectively. A full kinematic assessment was performed in each of the following conditions: (1) intact knee, (2) after sectioning of the anterior cruciate ligament (ACL), (3) after sectioning of the ACL and anterolateral ligament, (4) after isolated ACLR, and (5) after combined ACLR and Lemaire LET and combined ACLR and ALLR. ALLR was performed using the gracilis tendon, whereas the modified Lemaire procedure was performed using the central strip of the iliotibial band. The different states were compared using a Tukey paired comparison test. RESULTS: In knees with combined deficiency of the ACL and anterolateral structures, anterior translation and internal rotation remained significantly increased after isolated ACLR compared with the intact knee (+2.33 ± 1.44 mm and +1.98° ± 1.06°, respectively; P < .01). On the other hand, the addition of ALLR or modified Lemaire LET to ACLR restored anterior translation and internal rotation to values similar to those in the intact knee. The 2 anterolateral procedures did not show statistically significantly different values for both tests. This difference was 0.67 ± 1.46 mm for anterior translation (P = .79) and 0.11° ± 1.11° for internal rotation (P = .99). CONCLUSIONS: In knees with ACL and anterolateral deficiency, combined ACLR and anterolateral reconstruction restored the native knee stability in anterior translation and internal rotation contrary to isolated ACLR. In addition, both types of extra-articular reconstruction-ALLR and modified Lemaire LET-were similar in terms of restoring knee kinematics, and neither overconstrained the knee. CLINICAL RELEVANCE: In knees with deficiency of the ACL and anterolateral structures, combined ACLR and anterolateral reconstruction increased knee stability at time zero after surgery. This biomechanical improvement could be responsible for the protective effect on ACL graft and meniscal repair reported in the literature after the combined procedure.

Femoral insertion site in medial patellofemoral ligament reconstruction.

BACKGROUND: The optimal femoral insertion point in MPFL (medial patellofemoral ligament)-reconstruction still remains ambiguous. Three-dimensional knee simulations based on computerized tomography (CT) images acquired under physiological loading conditions give further insights to predict the optimal femoral insertion site of the MPFL. The hypothesis of the present study is that the optimal insertion point is not as reliable as thought and is dependent on subject-specific anatomical factors. METHODS: High-resolution 3D images of the knee were acquired in ten weight-bearing knees of healthy subjects in five flexion angles (0 to 120°). The distance between different femoral insertion points and two defined patellar points was computed in each position to quantify length of respective bundles and isometry of the femoral insertion site. RESULTS: The median length of both bundles was maximal in full extension (proximal bundle: 62.2mm and distal bundle: 59.9mm). The shortest ligament length was obtained in the flexion position 90° for bundle I (57.3mm) and 30° for bundle II (85.3mm). The calculated most isometric femoral attachment point showed a non-uniform distribution pattern related to anatomic landmarks. The radiographic landmark showed the worst isometric score value compared to virtually defined spots by surgeons and the computed most isometric point. CONCLUSIONS: This study provides results on the MPFL path length under physiological loading conditions using high-resolution bone geometry. The most important finding of this study was that the computed, best isometric femoral insertion point showed a variable anatomical distribution. This suggests that the optimal position for femoral MPFL-graft fixation is patient specific.

Complications after epiphyseal reconstruction of the anterior cruciate ligament in prepubescent children.

PURPOSE: Reconstruction of the anterior cruciate ligament (ACL) remains a major concern in the prepubescent, skeletally immature patient with wide open growth plates. Different surgical techniques have been proposed. This study reports the results and complications of ACL reconstruction in young children using an all epiphyseal technique. METHODS: Between 2006 and 2010, 12 patients (10-13 years, median 12.1 years) underwent epiphyseal primary ACL reconstruction, with a total of 13 knee procedures. Patients were assessed retrospectively with a median follow-up of 54 months (range 39-80 months) consisting of a clinical examination, instrumented arthrometer testing and radiological analysis. Functional status was assessed using the Lysholm knee score, Tegner activity scale and IKDC-2000 form. RESULTS: According to the IKDC examination form, five knees were rated as normal, six near normal and two abnormal. The median IKDC score at follow-up was 88.5 points (range 75-99 points). The mean side-to-side difference in KT-1000 ligament laxity testing was 1.5 mm (±2.5 mm). In two patients, reoperation was necessary due to graft failure. Two patients developed significant leg length inequality; one with 20 mm overgrowth and varus malalignment after re-reconstruction and the second developed arthrofibrosis and overgrowth of 16 mm. Four patients had minor limb length discrepancy ranging between +5 and +10 mm; no growth arrest was noted. One patient with an intact but slightly elongated graft required a meniscal suture 34 months after ACL reconstruction following a traumatic medial meniscal lesion. CONCLUSION: Despite using the epiphyseal technique in ACL reconstruction, relevant growth discrepancy can occur. Thereby, overgrowth rates appear to potentially pose a major clinical problem, which has remained unreported so far. Overall, there is a considerable high risk of complications in this patient group. LEVEL OF EVIDENCE: IV.

Unicompartmental knee arthroplasty MRI: impact of slice-encoding for metal artefact correction MRI on image quality, findings and therapy decision.

OBJECTIVES: To evaluate the impact of slice-encoding for metal artefact correction (SEMAC) on image quality, findings, and therapy decision in patients with unicompartmental knee arthroplasty (UKA). METHODS: Forty-five painful UKAs were examined at 1.5T-MRI (STIR, proton-density(PD)-weighted sequence, each with SEMAC and high-bandwidth). Artefact size, image quality, anatomic depiction, and clinically relevant findings were compared between SEMAC and high-bandwidth (2 readers). In 30 patients, therapy decision was retrospectively assessed by two orthopaedic surgeons without MRI, with high-bandwidth-MRI, and with SEMAC-MRI. RESULTS: SEMAC reduced mean artefact size for STIR (11.8 cm(2) vs. 37.7 cm(2)) and PD (16.8 cm(2) vs. 18.9 cm(2)), p < 0.0005 for both comparisons. SEMAC showed more blurring than high-bandwidth, p < 0.0005. STIR-SEMAC revealed more bone marrow oedema (29 vs. 18 patients, p = 0.001, 30 vs. 13 patients, p < 0.0005, for reader 1 and 2 respectively). PD-SEMAC was worse in detecting meniscal lesions (6 missed, p = 0.031, 9 missed, p = 0.004, by reader 1 and 2 respectively) than PD-high-bandwidth. Revision-surgery was chosen in 12 and 11 patients without MRI (surgeon 1 and 2), with high-bandwidth-MRI in 15 and 14 patients, and with SEMAC-MRI in 19 and 14 patients. CONCLUSIONS: STIR-SEMAC was useful in detecting bone marrow oedema and influenced the orthopaedic surgeons' decisions towards surgery, while PD-SEMAC showed no clinical benefit. KEY POINTS: • Slice-encoding for metal artefact correction (SEMAC) MRI reduces metal-induced artefact size. • STIR SEMAC detects more bone marrow oedema in painful unicompartmental knee arthroplasty. • STIR SEMAC can help the orthopaedic surgeon with decision making. • PD SEMAC suffers from blurring of images, potentially masking relevant meniscal lesions. • PD SEMAC does not improve cartilage lesion detection in the non-operated compartments.

Early serum procalcitonin level after primary total hip replacement.

BACKGROUND: Procalcitonin (PCT) is a useful surrogate marker for the differentiation of postoperative infection and unspecific inflammatory reaction after surgery. It is known that postoperative course of the PCT serum level varies with type of surgery. No data exists about the postoperative course of serum PCT levels after primary total hip replacement (THR). PURPOSE: To characterize early postoperative serum PCT levels in uneventful primary THR compared to postoperative levels of different frequently used inflammatory blood parameters. METHOD: We prospectively investigated 31 patients. Blood samples were taken preoperatively and for 5 days postoperatively. PCT levels were compared with C-reactive protein (CRP), interleukin-6 (IL-6), and blood leucocyte counts (WBC). RESULTS: In uneventful THR PCT levels showed a uniform low-level course with a peak at the second postoperative day. At the fifth day values returned to almost preoperative levels. On contrary, CRP levels remained high during the entire observational period. Only IL-6 levels showed a peak at postoperative day one with a quick and uniform return to preoperative levels. CONCLUSION: Similar to observations in cardiothoracic, intestinal, and neural surgeries, postoperative course of PCT after primary THR showed a uniform low-level course with a peak at the second postoperative day but below expected levels in systemic infections.

Spontaneous reduction of spondylolisthesis during growth: a case report.

Isthmic spondylolisthesis is a common cause of low back pain in children. It is associated with a defect in the pars interarticularis of the vertebra. The treatment depends on the clinical course and degree of spondylolisthesis. Low-grade isthmic spondylolisthesis usually shows a benign course without significant progression and therefore, conservative treatment is advised. Although isthmic pars defect can heal, initial existing degree of slippage persists. A complete reversion of deformity was never described yet. We present the case of a 7½-year-old girl with symptomatic grade 2 isthmic spondylolisthesis according to the Meyerding classification. Without any specific therapy, there was a radiologically documented near total reversion of slippage and total relief of clinical symptoms during 8 years of follow-up. Computed tomography scan after this period showed persisting pars interarticularis defect without signs of healing. This case report indicates that during growth, spontaneous reversion of vertebral slip in isthmic spondylolisthesis can occur, even without healing of the pars defect.