Ruminococcus gnavus total hip arthroplasty infection in a 62-year-old man with ulcerative colitis.

We report the case of a total hip arthroplasty infection caused by Ruminococcus gnavus in a 62-year-old man with ulcerative colitis. The bacterium was perfectly identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry.

Reduced levels of mesenchymal stem cells at the tendon-bone interface tuberosity in patients with symptomatic rotator cuff tear.

PURPOSE: While the use of bone marrow concentrate (BMC) has been described in the treatment of rotator cuff tears, the impact of a rotator cuff injury on the mesenchymal stem cells (MSCs) content present in the human shoulder has not been determined, especially with regard to changes in the levels of MSCs at the tendon-bone interface. With the hypothesis that there was a decreased level of MSCs at the tendon-bone interface tuberosity in patients with rotator cuff tear, we assessed the level of MSCs in the tuberosity of the shoulder of patients undergoing a rotator cuff repair. METHODS: We analysed the data of 125 patients with symptomatic rotator cuff tears and of 75 control patients without rotator cuff injury. We recorded the following data: size of tear, number of torn tendons, aetiology of the tear, lag time between onset of shoulder symptoms/injury and repair, and also fatty infiltration of muscles. Mesenchymal stem cell content at the tendon-bone interface tuberosity was evaluated by bone marrow aspiration collected in the humeral tuberosities of patients at the beginning of surgery. RESULTS: A significant reduction in MSC content (from moderate, 30-50 %, to severe >70 %) at the tendon-bone interface tuberosity relative to the MSC content of the control was observed in all rotator cuff repair study patients. Severity of the decrease was statistically correlated to a number of factors, including the delay between onset of symptoms and surgery, number of involved tendons, fatty infiltration stage and increasing patient age. CONCLUSION: This study demonstrates that the level of MSCs present in the greater tuberosity of patients with a rotator cuff tear decreases as a function of a number of clinical factors, including lag time from tear onset to treatment, tear size, number of tears and stage of fatty infiltration, among others. This information may help the practices in using biologic augmentation of a rotator cuff repair.

Biologic augmentation of rotator cuff repair with mesenchymal stem cells during arthroscopy improves healing and prevents further tears: a case-controlled study.

PURPOSE: The purpose of this study was to evaluate the efficiency of biologic augmentation of rotator cuff repair with iliac crest bone marrow-derived mesenchymal stem cells (MSCs). The prevalence of healing and prevention of re-tears were correlated with the number of MSCs received at the tendon-to-bone interface. METHODS: Forty-five patients in the study group received concentrated bone marrow-derived MSCs as an adjunct to single-row rotator cuff repair at the time of arthroscopy. The average number of MSCs returned to the patient was 51,000 ± 25,000. Outcomes of patients receiving MSCs during their repair were compared to those of a matched control group of 45 patients who did not receive MSCs. All patients underwent imaging studies of the shoulder with iterative ultrasound performed every month from the first postoperative month to the 24th month. The rotator cuff healing or re-tear was confirmed with MRI postoperatively at three and six months, one and two years and at the most recent follow up MRI (minimum ten-year follow-up). RESULTS: Bone marrow-derived MSC injection as an adjunctive therapy during rotator cuff repair enhanced the healing rate and improved the quality of the repaired surface as determined by ultrasound and MRI. Forty-five (100 %) of the 45 repairs with MSC augmentation had healed by six months, versus 30 (67 %) of the 45 repairs without MSC treatment by six months. Bone marrow concentrate (BMC) injection also prevented further ruptures during the next ten years. At the most recent follow-up of ten years, intact rotator cuffs were found in 39 (87 %) of the 45 patients in the MSC-treated group, but just 20 (44 %) of the 45 patients in the control group. The number of transplanted MSCs was determined to be the most relevant to the outcome in the study group, since patients with a loss of tendon integrity at any time up to the ten-year follow-up milestone received fewer MSCs as compared with those who had maintained a successful repair during the same interval. CONCLUSION: This study showed that significant improvement in healing outcomes could be achieved by the use of BMC containing MSC as an adjunct therapy in standard of care rotator cuff repair. Furthermore, our study showed a substantial improvement in the level of tendon integrity present at the ten-year milestone between the MSC-treated group and the control patients. These results support the use of bone marrow-derived MSC augmentation in rotator cuff repair, especially due to the enhanced rate of healing and the reduced number of re-tears observed over time in the MSC-treated patients.

Intrinsic graft laxity variation with open kinetic chain exercise after anterior cruciate ligament reconstruction: A non-randomized controlled study.

OBJECTIVES: To determine whether quadriceps and hamstring strengthening in a rehabilitation program involving early open kinetic chain (OKC) and/or closed kinetic chain (CKC) knee joint exercises had an influence on graft laxity at 1, 3, and 6 months after anterior cruciate ligament reconstruction (ACLR). DESIGN: Retrospective study. METHODS: Two groups (n = 53) of ACLR patients (combination of OKC and CKC exercises group compared to a CKC exercise group) were recruited. OKC protocol was introduced at 2 weeks post-operatively without external resistance and progressed at 4 weeks with load. Comparative ACL graft laxity measurement and isokinetic strength testing were prospectively performed up to 6 months in both groups. RESULTS: No significant differences were observed in the knee laxity at 1 (p = 0.263), 3 (p = 0.263), and 6 months (p = 0.256) follow up between the groups. Similarly, no significant results were observed in within-group knee laxity between 1 and 6 months after ACLR in the intervention (p = 0.155) and control group (p = 0.690). CONCLUSION: The early initiation of OKC along with CKC exercises doesn't seem to increase the ACLR graft laxity as compared to a rehabilitation program with only CKC exercises.

Safety of a novel high tibial osteotomy locked plate fixation for immediate full weight-bearing: a case-control study.

PURPOSE: The safety and efficacy of the novel Limmed® system (locked plate fixation) for immediate full weight-bearing after medial opening wedge high tibial osteotomy (HTO) were evaluated in patients with symptomatic varus gonarthrosis. METHODS: A case series of 85 consecutive osteotomies performed with Limmed® locked plate fixation for medial opening wedge HTO was compared to a historical matched case-control series of 85 HTOs (85 patients) performed using the same implant without locked screws. Subjects were observed at seven and 15 days and three, six and 12 months after surgery. Endpoints for evaluation included the reporting of adverse events, weight-bearing status without pain, radiographic evidence of bony union and changes in correction angle during healing. RESULTS: Statistically significant differences were seen between groups in terms of safety (thrombophlebitis), time to weight-bearing, radiographic union and radiographic stability between the two groups. Patients of the Limmed® group reported less thrombophlebitis (one versus nine), outcome with shorter time for full weight-bearing (average 45 days difference, p = 0.01) and a shorter time for union (average four weeks difference). At the one-year follow-up the post-operative hip-knee-ankle angle was 4.2° of valgus in the Limmed® group and 2° of valgus in the control group. The adjusted mean difference of 2.2° was significant (p = 0.02) and related to loss of correction during healing in the control group with difference in implant stability. The severity of pain, knee score and walking ability improved in both groups with a significant difference before the third month (quicker for Limmed® group), while at the most recent follow-up only the difference for mobility in flexion was significant. CONCLUSIONS: The Limmed® medial opening wedge HTO system represents a novel method of achieving a reliable correction while producing a stable fixation allowing satisfactory stability and bone healing with immediate full weight-bearing.

Evaluation of Muscle Strength and Graft Laxity With Early Open Kinetic Chain Exercise After ACL Reconstruction: A Cohort Study.

Background: Open kinetic chain (OKC) exercise is an effective method to improve muscle function during rehabilitation after anterior cruciate ligament reconstruction (ACLR); however, there is controversy about its use in the early phase of rehabilitation. Purpose: To determine (1) whether the use of OKC and closed kinetic chain (CKC) exercises improves quadriceps and hamstring strength in the early phase of rehabilitation after ACLR and (2) whether the early use of OKC exercise affects graft laxity at 3 and 6 months postoperatively in patients with a hamstring tendon graft. Study Design: Cohort study; Level of evidence, 3. Methods: This study included an intervention group that underwent OKC + CKC exercises (n = 51) and a control group that underwent CKC exercise only (n = 52). In the intervention group, OKC exercise for the quadriceps and hamstring was started at 4 weeks after ACLR. At 3 and 6 months postoperatively, isokinetic testing was performed to calculate the limb symmetry index (LSI) and the peak torque to body weight ratio (PT/BW) for the quadriceps and hamstring. Anterior knee laxity was measured by an arthrometer. Results: At 3 and 6 months postoperatively, quadriceps strength was higher in the intervention group than in the control group for the LSI (3 months: 76.14% ± 0.22% vs 46.91% ± 0.21%, respectively; 6 months: 91.05% ± 0.18% vs 61.80% ± 0.26%, respectively; P < .001 for both) and PT/BW (3 months: 1.81 ± 0.75 vs 0.85 ± 0.50 N·m/kg, respectively; 6 months: 2.40 ± 0.73 vs 1.39 ± 0.70 N·m/kg, respectively; P < .001 for both). There were similar findings regarding hamstring strength for the LSI (3 months: 86.13% ± 0.22% vs 64.26% ± 0.26%, respectively; 6 months: 91.90% ± 0.17% vs 82.42% ± 0.24%, respectively; P < .001 at three months, P = .024 at 6 months) and PT/BW (3 months: 1.09 ± 0.36 vs 0.67 ± 0.39 N·m/kg, respectively; 6 months: 1.42 ± 0.41 vs 1.07 ± 0.39 N·m/kg, respectively; P < .001 for both). No significant difference in laxity was observed between the intervention and control groups at 3 or 6 months. Conclusion: Early use of OKC exercise for both the quadriceps and the hamstring, in addition to conventional CKC exercise, resulted in better correction of quadriceps and hamstring strength deficits without increasing graft laxity.

Computer-assisted navigation in patellofemoral arthroplasty: a new technique to improve rotational position of the trochlea.

BACKGROUND: Maltracking or subluxation is one of the complications of patellofemoral arthroplasty. QUESTIONS/PURPOSES: We questioned whether the computed navigation system can improve patellar tracking in patients with patellofemoral arthroplasty (PFA). METHODS: Between 2007 and 2010 we performed 15 patellofemoral arthroplasties using the Ceraver PFA and navigation assistance. Fifteen other patients underwent surgery without navigation during the same period and acted as a control group. The rotation of the native trochlea as measured using the epicondylar line as a reference before surgery and the rotation of the trochlear component and the trochlear twist angle were assessed with computed tomography (CT) scan after surgery. RESULTS: The mean follow-up was 3 years (range, 2-5 years). The group with navigation had no patellofemoral complications and better clinical scores. The group without navigation had abnormal patellofemoral tracking in 5 of the 15 patients. CT scan demonstrated excessive internal component rotation, as compared with patients without complications. This excessive internal rotation was proportional to the severity of the patellofemoral maltracking. CONCLUSIONS: The short-term results suggest that navigation can lead to better trochlear rotation which, in our hands, is associated with fewer cases of patellar maltracking and better overall clinical scores.

Outcome of total knee arthroplasty after high tibial osteotomy: does malalignment jeopardize the results when using a posterior-stabilized arthroplasty?

BACKGROUND: The controversy regarding the outcome of total knee arthroplasties after high tibial osteotomy may relate to malalignment secondary to overcorrection after high tibial osteotomy (HTO) [1, 2] and to the type of arthroplasty itself (posterior-stabilized arthroplasty or posterior cruciate ligament-retaining prosthesis). QUESTIONS/PURPOSE: We asked two questions: (1) Would a posterior-stabilized arthroplasty provide sufficient constrain and improve pain and function in patients with severe malalignment due to a previous HTO? (2) Will malalignment of the previous HTO jeopardize the long-term results of a total knee reconstruction with a posterior-stabilized implant? PATIENTS AND METHODS: We retrospectively reviewed 25 posterior-stabilized TKAs in 25 patients with severe valgus deformity after HTO (ranging from 10° to 20° of valgus) and compared the results with a series of matched 25 posterior-stabilized TKAs in 25 patients with normocorrection after HTO ranging from 5° of valgus to 5° of varus. Clinical, operative, and radiographic data were reviewed. Minimum follow-up was 10 years after the arthroplasty (average, 15 years; range, 10-20 years). RESULTS: All the knees had standard posterior-stabilized total knee arthroplasty implants. Patients with an overcorrected HTO were more likely to require a soft tissue release to balance the knee. However, Average Knee Society and Function Score improved, respectively, from 48 to 85 and from 50 to 90 points in the severely overcorrected group, versus, respectively, 50 to 89 and 52 to 97 in the normocorrected group, but the range of mobility was superior for patients with normal alignment. Fifteen-year survivorship after the arthroplasty comparison showed no significant difference between the two groups (one revision in each group). CONCLUSIONS: Patients with an overcorrected HTO are more likely to require a soft tissue release to balance the knee. However, both groups show improvements in function and pain. With a posterior-stabilized arthroplasty, the degree of deformity has no impact on the longevity of the TKA.