No significant improvement in neuromuscular proprioception and increased reliance on visual compensation 6 months after ACL reconstruction.

PURPOSE: To determine the contributions of proprioceptive and visual feedbacks for postural control at 6 months following ACLR, and to determine their associations with knee laxity, isokinetic tests and clinical scores. STUDY DESIGN: Level IV, Case series. METHODS: Fifty volunteers who received ACLR between May 2015 and January 2017 were prospectively enrolled, and at 6 months following ACLR, postural stability was assessed. Somatosensory ratios (somatic proprioception), and visual ratios (visual compensation), were calculated to evaluate the use of sensory inputs for postural control. Univariable regression analyses were performed to determine associations of somatosensory and visual ratios with knee laxity, isokinetic tests and clinical scores. RESULTS: At 6 months following ACLR, the somatosensory ratio did not change, while the visual ratio decreased significantly from 5.73 ± 4.13 to 3.07 ± 1.96 (p = 0.002), indicating greater reliance on visual cues to maintain balance. Univariable analyses revealed that the somatosensory ratio was significantly lower for patients who performed aquatic therapy (ß = -0.50; p = 0.045), but was not associated with knee laxity, muscle strength or clinical scores. An increased visual ratio was associated with patients who received hamstrings tendon autografts (ß = 1.32; p = 0.049), but was not associated with knee laxity, muscle strength or clinical scores. CONCLUSION: At 6 months following ACLR, visual ratios decreased significantly, while somatosensory ratios did not change. This may suggest that there is little or no improvement in neuromuscular proprioception and therefore greater reliance on visual cues to maintain balance. The clinical relevance of this study is that posturography can provide useful information to help research following ACLR and to predict successful return to play.

Excellent outcomes for lateral unicompartmental knee arthroplasty: Multicenter 268-case series at 5 to 23 years' follow-up.

INTRODUCTION: Isolated lateral compartment osteoarthritis of the knee (LCOA) is 10 times less frequent than medial compartment involvement. Long-term assessments of unicompartmental knee arthroplasty (UKA) in this indication are rare, with small series. HYPOTHESIS: Survival and functional outcome of lateral UKA in a large series are quite acceptable; the strategy is suited for isolated LCOA. MATERIAL AND METHOD: A multicenter retrospective study in 6 French health establishments included all lateral UKAs performed between January 1988 and September 2014. Clinical data (range of motion, International Knee Society (IKS) knee and function scores, satisfaction), paraclinical data (radiologic angles) and complications were prospectively entered in medical files during follow-up and analyzed retrospectively at end of follow-up. RESULTS: During the study period, 311 lateral UKAs were performed in 295 patients, using 5 fixed-bearing implant models. Twenty-eight patients died within 5 years, and 15 (4.8%) were lost to follow-up. The series thus comprised 268 lateral UKAs in 63 male and 205 female patients, with a mean age of 68.8±10.5 years, including 7 cases of post-traumatic osteoarthritis and 4 of aseptic osteonecrosis. Mean follow-up was 9.1 years (range, 5-23 years), implant survivorship with failure defined as all-cause revision surgery was 85.4% at 10 years and 79.4% at 20 years. At last follow-up, IKS knee score was 87.0 and IKS function score 80.2. Maximal flexion was 125°. 94.3% of patients were satisfied or very satisfied. The main cause of revision surgery was osteoarthritis in another knee compartment (66,7%, n=26). CONCLUSION: Lateral UKA showed good survivorship, comparable to medial UKA, with good functional results and excellent long-term satisfaction. LEVEL OF EVIDENCE: IV, retrospective cohort study.

Factors affecting outcome of ACL reconstruction in over-50-year-olds.

INTRODUCTION: With increasing life expectancy and ever-improving quality of life in industrialized countries, functional demand and sports levels are increasing in older subjects, who are thus exposed to central pivot lesions almost as much as younger ones. While non-operative treatment provides acceptable results, it entails significant reduction in sports level. The aim of the present study was to analyze medium-term clinical, functional and radiological results of anterior cruciate ligament (ACL) reconstruction in over-50-year-olds, in order to identify factors for failure. HYPOTHESIS: The study hypothesis was that surgical management provides good results if patient selection is rigorous. PATIENTS AND METHODS: A multicenter retrospective study included 398 patients undergoing ACL reconstruction between April 1, 2009 and December 6, 2016. Inclusion criteria comprised: age≥50 years, with proven ACL tear. Preoperatively, clinical work-up was supplemented by measurement of differential anterior laxity and radiologic assessment of cartilage status. Functional level was assessed on the objective IKDC score. Intraoperative data comprised type of graft and meniscal and cartilage status. The same parameters were assessed postoperatively. Functional results were assessed on objective IKDS, KOOS and ACL-RSI scores. RESULTS: The mean follow-up was 42.2 months. The mean improvement in differential anterior laxity was 4.2mm. Pivot-shift showed improvement, with 97% absent or glide (p<0.001). Objective IKDC score showed significant improvement (p<0.0001). 23% of patients had poor clinical results: IKDC C or D. Preoperative explosive pivot-shift (p<0.0001), medial tibiofemoral osteoarthritis (p<0.0001) and medial meniscus lesion (p<0.002) emerged as risk factors for poor functional outcome. CONCLUSION: ACL reconstruction in over-50-year-olds provided satisfactory clinical and functional results. Rigorous patient selection is mandatory, as radiologic signs of medial tibiofemoral osteoarthritis indicate a risk of poor outcome. Surgery may be proposed in patients with high functional and athletic demand, before medial meniscal lesions can set in. In case of explosive pivot shift, associated anterolateral reconstruction should be considered.

Anteversion and length of the femoral tunnel in ACL reconstruction: in-vivo comparison between rigid and flexible instrumentation.

BACKGROUND: Due to it being tangential to the distal femoral axis, the anteromedial portal presents significant risk of causing iatrogenic damage, and of producing tunnels that are too short for optimal osseointegration. Flexible reamers were developed to eliminate the need for knee hyperflexion and offer better-controlled orientation of the femoral tunnel. We aimed to compare the anteversion and length of femoral tunnels drilled using flexible reamers to those drilled using rigid reamers. METHODS: Between May 2012 and December 2013, all patients receiving ACL reconstruction performed by one surgeon were operated on using either a rigid or a flexible reamer from the same supplier (Versi-Tomic® system, Stryker, Kalamazoo, Michigan). The height of each patient was recorded, and the length and anteversion of the femoral tunnels were measured intra-operatively and on true lateral radiographs, respectively. RESULTS: Thirty-seven patients underwent operations using the rigid instrumentation, and 43 using the flexible instrumentation. There was no statistically significant difference between the two groups in either sex or height (p = n.s.). The patients operated on using the rigid instrumentation had tunnels anteverted by 18.6° ± 6° and 33.6 ± 2.9 mm long. Those operated on using the flexible instrumentation had tunnels anteverted by 40° ± 2° and 41.1 ± 3.57 mm long. Both anteversion and tunnel length were significantly greater for tunnels drilled using the flexible instrumentation (p < 0.001). CONCLUSIONS: This study demonstrated that flexible reamers produce significantly more anteverted and longer femoral tunnels during ACL reconstruction than rigid reamers. Clinical studies remain necessary to assess the outcomes of ACL reconstruction using flexible reamers.

Proximal humeral bony adaptations with a short uncemented stem for shoulder arthroplasty: a quantitative analysis.

BACKGROUND: Short uncemented stems have recently been proposed as an alternative to classic long stems for shoulder arthroplasty. The early results are promising, but bony adaptations of the proximal humerus have been reported. The aim of this study was to quantify these phenomena using the Ascend Flex stem and to determine the risk factors. MATERIALS AND METHODS: In a retrospective, single-center study, 183 shoulder arthroplasties were evaluated at 2-year follow-up. All patients underwent clinical evaluations preoperatively and at last follow-up. Radiographs were obtained preoperatively, postoperatively, and at last follow-up. Four types of bony adaptations were analyzed: medial cortical narrowing (MCN), medial metaphysis thinning (MMT), lateral metaphysis thinning (LMT), and under-the-baseplate osteolysis. The risk factors were analyzed in a multivariate model. RESULTS: MCN was found in 72.6% of cases and was severe (>50%) in 4.4%. MMT was found in 46.4% of cases and was severe in 3.3%. LMT was found in 9.8% of cases and was severe in 2.8%. The risk factors for MCN were the distal filling ratio, osteoporosis, and female sex, whereas MMT and LMT were only influenced by stem axis deviation. Under-the-baseplate osteolysis was found in 34.4% of cases. No influence of bony adaptations on the clinical outcomes was observed. We found no complications related to the stem or to stem loosening. CONCLUSION: The radiographic evolution was satisfactory at mid-term follow-up. Bony adaptations seemed to be limited phenomena, without any observed consequence. Avoiding excessive filling and axis deviation may limit these phenomena.

Comparison of an Innovative Rehabilitation, Combining Reduced Conventional Rehabilitation with Balneotherapy, and a Conventional Rehabilitation after Anterior Cruciate Ligament Reconstruction in Athletes.

BACKGROUND: Instability of the knee, related to anterior cruciate ligament injury, is treated by surgical reconstruction. During recovery, a loss of proprioceptive input can have a significant impact. Few studies have evaluated the benefits of rehabilitation of the knee in aquatic environment on functional outcomes. OBJECTIVE: This study aimed to compare an innovative rehabilitation protocol combining reduced conventional rehabilitation with aquatic rehabilitation, with a conventional rehabilitation, according to the National French Health Authority, in terms of kinetics, development of proprioceptive skills, and functional improvement of the knee. METHODS: 67 patients, who were amateur or professional athletes, were randomized into two groups: 35 patients followed the conventional rehabilitation protocol (Gr1) and 32 patients followed the innovative rehabilitation protocol (Gr2). Patients were evaluated before surgery, and at 2 weeks, 1, 2, and 6 months after surgery using posturography, and evaluation of muscular strength, walking performance and proprioception. This study is multicenter, prospective, randomized, and controlled with a group of patients following conventional rehabilitation (level of evidence I). RESULTS: For the same quality of postural control, Gr2 relied more on somesthesia than Gr1 at 6 months. The affected side had an impact on postural control and in particular on the preoperative lateralization, at 2 weeks and at 1 month. Lateralization depended on the affected knee, with less important lateralization in Gr2 preoperatively and at 1 month. The quadriceps muscular strength was higher in Gr2 than in Gr1 at 2 and 6 months and muscle strength of the external hamstring was greater in Gr2 than in Gr1 at 6 months. The isokinetic test showed a greater quadriceps muscular strength in Gr2. Gr2 showed a greater walking distance than Gr1 at one month. Gr2 showed an improvement in the proprioceptive capacities of the operated limb in flexion for the first 2 months. CONCLUSION: The effectiveness of the innovative rehabilitation program permits faster recovery, allowing for an earlier return to social, sporting, and professional activities. Faster retrieval of knee function following aquatic rehabilitation would prevent both short-term risk of lesions of the contralateral limb due to overcompensation and long-term risk of surgery due to osteoarthritis. REGISTRATION OF CLINICAL TRIALS: NCT02225613.

A differential pumping system to deliver windowless VUV photons at atmospheric pressure.

In order to deliver VUV (vacuum ultraviolet) photons under atmospheric pressure conditions, a differential pumping system has been built on the DISCO beamline at the SOLEIL synchrotron radiation facility. The system is made of four stages and is 840 mm long. The conductance-limiting body has been designed to allow practicable optical alignment. VUV transmission of the system was tested under air, nitrogen, argon and neon, and photons could be delivered down to 60 nm (20 eV).

Surgical technique: the anterosuperior approach for reverse shoulder arthroplasty.

BACKGROUND: The anterosuperior approach used for reverse shoulder arthroplasty is an intermediate between the transacromial approach originally proposed by Paul Grammont and the anterosuperior approach described by D. B. Mackenzie for shoulder arthroplasty. As an alternative to the deltopectoral approach, the anterosuperior approach has the advantages of simplicity and postoperative stability. DESCRIPTION OF TECHNIQUE: The anterior deltoid is divided from the anterior edge of the acromioclavicular arch, allowing exposure to the glenoid for glenosphere implantation. PATIENTS AND METHODS: We used the findings of published studies to assess instability, function and pain scores, scapular notching, and complications after this approach. RESULTS: In a comparison of the deltopectoral and anterosuperior approaches in 527 reverse arthroplasties with a minimum 2-year followup, postoperative instability rate was greater with the deltopectoral (5.1%) than with the anterosuperior (0.8%) approach. Other published studies confirm this finding. No differences in Constant-Murley score or active mobility were found. Scapular notching occurred at similar rates after the anterosuperior (74%) and deltopectoral (63%) approaches. Humeral diaphyseal fracture rates were similar, whereas the acromial fracture rate was higher using the deltopectoral approach. Loosening tended to occur more often with the anterosuperior approach. CONCLUSIONS: The anterosuperior approach can be used in primary and revision reverse shoulder arthroplasty, as well as in acute humeral head fracture. Its main apparent advantages are simplicity, ease of axial humerus preparation, quality of frontal exposure of the glenoid, and due to subscapularis tendon preservation, a low risk of postoperative instability. Its drawbacks are risk of inaccurate glenoid positioning, axillary nerve palsy, and deltoid weakening.