Residual Instability Research Articles

Characteristics of Chronic Ankle Instability Requiring Both Anterior Talofibular and Calcaneofibular Ligament Repair

Chronic ankle instability (CAI) leads to the ankle osteoarthritis (OA), and ligament repair is performed to restore ankle stability. However, anterior talofibular ligament (ATFL) repair alone is not sufficient to stabilize the ankle in some cases, which additionally require calcaneofibular ligament (CFL) repair. This study aimed to explore characteristics of CAI that necessitated the repair of both ATFL and CFL. Forty-three patients (44 ankles) with CAI treated operatively were retrospectively reviewed. After ATFL repair, patients with residual ankle instability revealed by the varus stress under fluoroscopy additionally underwent CFL repair. Preoperative condition and intraoperative findings of the combined ATFL and CFL repair (AC) (n = 24) and only ATFL repair (A) (n = 20) groups were compared. The ankle activity score of group AC was significantly higher (p < .05) than that of group A. OA changes at the medial gutter were observed in 62.5% (15/24) in the group AC and 20% (4/20) in group A. Chondral/osteochondral lesions were seen in 66.7% (16/24) in the group AC and 20% (4/20) in group A. The remnant quality in group AC was inferior to that of group A. CAI that necessitated both ATFL and CFL repair exhibited characteristic findings such as high ankle activity score, high rate of chondral/osteochondral lesions and/or OA changes, and poor quality of ATFL remnants compared to those in CAI that required only ATFL repair. The repair of both ATFL and CFL should be considered in CAI which exhibit these characteristics to ensure complete correction of the instability.

Anteromedial Tibial Attachment in Single-Bundle Anterior Cruciate Ligament Reconstruction Can Represent Normal Kinematics in Computer Simulation.

Tunnel position during anterior cruciate ligament (ACL) reconstruction is considered as an important factor to restore normal knee kinematics and to gain better clinical outcomes. It is still unknown where the optimal femoral and tibial tunnel position is located in single-bundle (SB) ACL reconstruction. The purposes of this study were to analyze the knee kinematics with various graft positions and to propose the optimal graft position during SB ACL reconstruction. A musculoskeletal computer simulation was used to analyze knee kinematics. Four attachments on the femoral side (anteromedial [AM], mid, posterolateral [PL], and over-the-top positions) and three attachments on the tibial side (AM, middle, and PL positions) were determined. The middle-bundle attachment was placed at the midpoint of the AM and PL bundle attachments for the femoral and tibial attachments. SB ACL reconstruction models were constructed to combine each of the four femoral attachments with each of three tibial attachments. Kinematic comparison was made among a double-bundle (DB) model and 12 SB reconstruction models during deep knee bend and stair descent activity. The tunnel position of the tibia had greater effect of knee kinematics than that of the femur. AM tibial attachment models showed similar medial and lateral anteroposterior positions to the DB model for both activities. Axial rotation in the AM tibial attachment models was similar to the DB model regardless of the femoral attachment, whereas greater maximum axial rotation was exhibited in the PL tibial attachment models, especially during stair descent activity. AM tibial attachment can represent normal knee kinematics, whereas the PL tibial attachment can induce residual rotational instability during high-demand activities. The AM tibial tunnel is recommended for SB ACL reconstruction.

Does anterolateral ligament internal bracing improve the outcomes of anterior cruciate ligament reconstruction in patients with generalized joint hypermobility?

Generalized joint hypermobility (GJH) is a risk factor for anterior cruciate ligament (ACL) injury and ACL graft failure and is considered an indication for anterolateral ligament (ALL) reconstruction. The aim of this retrospective study was to compare functional outcomes, rupture rates, and residual instability in patients with GJH undergoing isolated ACL reconstruction or combined ACL reconstruction and ALL augmentation with internal bracing (ALL-IB). Sixty-eight patients with GJH and unilateral ACL injury were randomly assigned to undergo either isolated ACL reconstruction (Group 1) or combined ACL reconstruction and ALL-IB (Group 2). The patients were evaluated pre- and postoperatively; their medical histories; physical examination results; anterior knee translation, as measured using the KT-1000 arthrometer; and scores of validated knee assessments were recorded. Groups 1 and 2 consisted of 37 and 31 patients, respectively. The mean follow-up was 30.1±4.1 and 28.1±2.9 months, respectively. In the final evaluation, the patients in Group 2 showed better rotational stability, as evaluated by the pivot-shift test (p=0.013); better anteroposterior stability, as evaluated by KT-1000 arthrometry (p=0.001); similar function (p=0.14 for the Lysholm, p=0.11 for the Cincinnati, and p=0.19 for the International Knee Documentation Committee subjective score); and failure rate (p=0.41). The functional outcomes were similar between the groups. The stability outcomes after combined ACL and ALL-IB were better than those after isolated ACL reconstruction in patients with GJH. However, the technique and its results need to be validated in larger patient series and prospective randomized controlled trials.

Quadrimalleolar Fractures of the Ankle: Principles and Medium-Term Results of Surgical Fixation

Category:Ankle; TraumaIntroduction/Purpose:Over the last decade, much attention has been paid to the fractures of the posterior malleolus as it became obvious that the mere presence of a posterior tibial fragment is associated with a less favorable prognosis in malleolar fractures. It seems logical to pay the anterior restraints of the ankle joint a similar attention as to the posterior ones. The anteriolateral distal tibia may be considered a 'fourth' or anterior malleolus. Here, we present a technique of fixation of trimalleolar fractures with additional fracture of the anterior tibial tubercle ('quadrimalleolar') or anterior fibular rim ('quadrimalleolar equivalent').Methods:Twenty-four patients with a mean age of 60 years were treated with open reduction and internal fixation of all 4 malleoli. There were 17 quadrimalleolar and 6 quadrimalleolar equivalent fractures. One patient had both anterior tibial and fibular avulsion fractures in addition to a trimalleolar ankle fracture. Surgical approaches and internal fixation were tailored individually. Twenty patients were operated in prone position with direct fixation of the posterior malleolus and 4 patients in supine position with indirect anterior to posterior screw fixation of the posterior malleolus under transfibular control of reduction.Results:After fixation of al 4 malleoli, only one patient (4%) required a syndesmotic screw for residual syndesmotic instability on intraoperative testing. There were no infections, and no wound healing problems. All patients went on to solid union. No late fusions were needed. Nineteen patients (79%) could be reevaluated after a mean of 77 months (range, 15 to 156 months) follow- up. The Foot Function Index averaged 15 (range, 50 to 0), the Olerud and Molander Score averaged 79 (range, 45 to 100) and the AOFAS Ankle and Hindfoot Scale averaged 87 (range, 39 to 100).Conclusion:Fixation of the anterior and posterior tibial fragments increases syndesmotic stability by providing a bone-to-bone fixation. Reduction of displaced anterior and posterior tibial rim fractures restores the physiological shape of the tibial incisura and therefore facilitates fibular reduction. In the majority of cases, this also restores articular congruity of the lateral tibial plafond.Anatomic reduction of the anterior and posterior malleolus in addition to medial and lateral malleolar fixation leads to favourable functional results despite a complex (quadrimalleolar) fracture pattern.

Chopart Fractures and Dislocations: Case Series and New Algorithm of Treatment

Category:TraumaIntroduction/Purpose:Chopart fractures and dislocations are one of the most commonly overlooked injuries of the foot. These injuries are still challenging in both diagnosis and treatment and result in a high degree of long-term disability. Recent studies have shown that around 30 to 40% of these injuries are not adequately diagnosed on first consultation, mainly because of their low incidence and high clinical variability/spectrum of injuries. Anatomical reduction of Chopart injuries seems to be the most important prognostic factor of functional outcomes. However, there is still no consensus or clear evidence-based guidelines on the management of these types of injuries. We report the result of our current management protocol and propose a new algorithm of management of Chopart Injuries.Methods:We present a case series of patients with Chopart fractures and fracture-dislocations admitted to a Level 1 Trauma center between March 2015 and April 2020. Demographic data, mechanism of injury, treatment and complications were obtained from clinical records. Classification of injuries according to Zwipp was performed. Standardized surgical management was performed in 1 or 2 stages, according to soft tissue status. Open reduction and internal fixation of associated fractures of the talus, navicular, calcaneus and cuboid was performed. In cases of severe articular comminution or presence of medial and/or lateral instability, transarticular bridge plating was indicated. Postoperative radiological assessment was performed with X-rays and CT scan. Outcomes were determined using the American Orthopaedic Foot & Ankle Society midfoot score (AOFAS), visual analogue scale (VAS), foot and ankle ability measure (FAAM) and the 12-item Short Form Survey (SF-12).Results:Thirty four patients (12 women) were included in this study with a mean age of 37 years. Mechanisms of injury were: motor vehicle accidents (n=12), low energy midfoot torsion (n=12), crushing injuries (n=7), fall from height (n=2) and firearm injury (n=1). Mean follow up was 39 months (ranging from 8 to 71 months). The mean AOFAS score 84.8 (SD 12.9), mean FAAM of 84.4% (SD 15.4) and mean VAS score was 3/10. In terms of quality of life, the SF-12 physical component score was 43.59 (SD 9.3), with a mental component score of 51.98 (SD 12.1). Secondary procedures included: hardware removal (n=23), midfoot fusion (n=3) and skin coverage procedures by plastic surgery (n=5).Conclusion:In this case series, a standardized strategy for the treatment of Chopart injuries including the use of external fixation, ORIF and transarticular plating is presented. Reestablishment of joint alignment of both columns (medial and lateral) is crucial to obtain acceptable functional outcomes. Transarticular fixation is a useful alternative to post-reduction residual instability and bridging of fractures with periarticular comminution. Functional and quality of life results on this series were acceptable and comparable to previous reports at minimum one year follow up. Long-term follow up is needed to further validate the proposed algorithm.

CLINICAL RESULTS OF MEDIAL PATELLOFEMORAL LIGAMENT RECONSTRUCTION.

ABSTRACTObjective: To assess clinical results of patients who underwent medial patellofemoral ligament (MPFL) reconstruction after a minimum of two years of follow-up.Methods: Patients’ medical records were assessed for residual instability, patient satisfaction, and post-operative functional outcomes.Results: Fifty-one patients were analyzed, out of which 56.87% were women. Patients’ mean age was 30.8 years (16 to 57 years). The mean follow-up time was 68.7 months (37 to 120 months). Length between first dislocation and surgery was less than 1 year for 58.82% of patients, between 1 and 5 years for 37.25%, and over 5 years for 3.93%. Patients showed a high degree of satisfaction (96.08% would undergo surgery again), with recurrence rate of 11.76%. Twenty-two patients reported knee symptoms, including pain from movements (72.72%), weakness (18.18%), constant pain (13.63%), and crepitus (4.54%). Considering dissatisfied patients, patients with dislocation recurrence, and patients with symptoms, five cannot practice physical activity, out of which only three blame their knee.Conclusion: MPFL reconstruction showed a recurrence rate of 11.7%, with high patient satisfaction, good functional results, and high rate of return to sports, after a minimum of two years of follow-up. Level of Evidence IV, Case Series.

Role of microendoscopic discectomy for the treatment of recurrent lumbar disc herniation: A retrospective review

Background: Recurrent herniation following lumbar disc excision has been reported in 5–11% of patients. There are very few studies on role and outcomes of minimally invasive techniques for the treatment of recurrent disc herniation.Study Design: A retrospective analytical study of 22 patients with recurrent lumbar disc herniation treated with minimally invasive techniques.Objectives: To analyze the role and scope of minimally invasive surgical techniques and consequent outcome in various cases of recurrent lumbar disc herniation.Method: Total 22 patients with recurrent lumbar disc herniations who underwent operations in the form of microendoscopic discectomy (MED) were studied for a period of 1 year. These cases of recurrent lumbar disc herniation with the perioperative data and clinical outcomes (according to modified Macnab criteria) upto 1 year follow up were compared with the previously published data.Results: Overall, the clinical outcomes were significantly excellent or good during and at 1 year follow-up. No case had to be converted to open procedure. Complications occurred in three cases including one incidental durotomy and two patients had recurrent disc herniation. No other significant morbidity including wound infection, neural injury or residual instability occurred till last follow-up. Operative duration, blood loss, complication rate and overall outcomes were statistically comparable to the previously published data.Conclusions: This study suggests that outcomes of minimally invasive techniques for treating recurrent lumbar disc herniation are equivalent to or even superior in some cases in which conventional open surgery was considered. The operative time, blood loss and complications of patients treated with revision MED were comparable to the previously published data. The procedure appears to be a safe and effective alternative with significant improvement in pain, disability, and faster return to work in case of recurrent lumbar disc herniation.

Arthroscopic Foveal Repair of the Triangular Fibrocartilage Complex Improved the Clinical Outcomes in Patients With Persistent Symptomatic Distal Radio-Ulnar Joint Instability After Plate Fixation of Distal Radius Fractures: Minimum 2-Year Follow-Up

To investigate the longitudinal trend of symptomatic distal radioulnar joint (DRUJ) instability after plate fixation for distal radius fractures (DRFs), determine which factors are associated with persistent symptomatic DRUJ instability, and evaluate the postoperative outcomes of arthroscopic foveal repair of the triangular fibrocartilage complex (TFCC) in patients with persistent symptomatic DRUJ instability after plate fixation for DRF. All consecutive patients who underwent plate fixation for DRF between January 2014 and December 2017 and were followed up for a minimum of 1 year were included in this retrospective study. DRUJ instability was evaluated by subjective ulnar wrist pain and physical examination that included foveal sign and ballottement testing every 2 months after surgery. In patients with persistent symptomatic DRUJ instability lasting >6 months, arthroscopic transosseous foveal repair was performed with consent. Clinical outcomes were evaluated at a minimum of 2 years after surgery. The Generalized Estimating Equation model was used to analyze the incidence rate trend of symptomatic DRUJ instability. Overall, 204 patients were included. The incidence of symptomatic DRUJ instability decreased gradually with time after fixation for DRF until 6 months and was maintained thereafter. Thirty-four of 204 patients (16.6%) had persistent symptomatic DRUJ instability. In multivariable analysis, only high-energy injury was an independent risk factor for persistent symptomatic DRUJ instability (P= .003; odds ratio= 3.599). Seventeen patients underwent arthroscopic foveal repair. The mean follow-up period thereafter was 28.6 months. All clinical outcomes improved significantly compared with preoperative values, and no patient had residual DRUJ instability. In patients who had persistent symptomatic DRUJ instability for >6 months after plate fixation for DRFs, arthroscopic foveal repair of the TFCC is considered as a treatment option. Arthroscopic foveal repair of the TFCC to stabilize the DRUJ provided satisfactory clinical and functional outcomes and decreased ulnar-side pain. Level IV, retrospective case series.

Defining length stability in paediatric femoral shaft fractures treated with titanium elastic nails.

IntroductionOptimal paediatric femoral shaft fracture patterns or lengths amenable to titanium elastic nail stabilization have not been well defined. The purpose of this study is to identify radiographic parameters predictive of treatment failure with flexible intramedullary nails based upon fracture morphology.MethodsA retrospective review was performed of all femoral shaft fractures treated with flexible intramedullary nails over a five-year period. All patients with at least six weeks of postoperative radiographic imaging were included. Fracture characteristics included location, pattern, length, obliquity, angulation, translation and shortening. Postoperative radiographs were reviewed to determine shortening and angulation.ResultsThere were 58 patients with 60 femoral shaft fractures stabilized with titanium nails, with 46 healing within acceptable parameters and 14 considered malunions. Six of the 14 malunions developed complications requiring early unplanned intervention. No patients in the treatment success group had a complication. Between the treatment success and failure groups, fracture pattern, location, length, obliquity, angulation, translation or shortening were not statistically different. Mean nail canal fill was significantly lower in the failure group (0.72 versus 0.81; p = 0.0146), with a receiver operating characteristic curve identifying canal fill 76% as the optimal threshold.ConclusionThis is the first study to measure the length and obliquity of paediatric femoral shaft fractures and to determine their relationship to radiographic alignment after healing. None of the preoperative fracture characteristics were predictive of malalignment or shortening. We recommend the use of larger nail sizes in the treatment of paediatric femoral shaft fractures, especially if there is concern for residual instability.Level of evidenceIV

Arthroscopic Repair of a Posterior Midcapsular Rupture Causing Posterior Shoulder Instability

Background: Gross posterior instability is rare and when found likely has an injury or deficiency to the posterior static restraints of shoulder associated with it. Traditionally, injuries to the posterior capsule have been difficult to diagnose and visualize with magnetic resonance imaging preoperatively, and very little literature regarding arthroscopic repair of posterior capsular tears exists currently. Indications: We present a repair of a posterior midcapsular and posterior labral tear in a 26-year-old man with recurrent left posterior shoulder instability using a novel all–arthroscopic technique. Technique Description: We performed a shoulder arthroscopy in a lateral decubitus position with the arm at 45° of abduction using standard posterior viewing and anterior working portals. Diagnostic arthroscopy revealed a large posterior midcapsular rupture approximately 2 cm lateral to the glenoid with an associated posterior labral tear. We created an accessory posterolateral portal with needle localization that was outside the capsular defect yet allowed access to the posterior labrum. Anatomic closure of the capsular tear was achieved arthroscopically with 3 interrupted No. 2 nonabsorbable sutures in a side–to–side fashion. Posterior labral repair and capsular shift were done to further address the instability using 2 knotless all–suture anchors percutaneously placed at the 7 o'clock and 9 o'clock position. We closed the posterior portal with a combination of curved and penetrating suture passers. Incisions were closed with interrupted 4-0 nylon. Postoperatively, the patient was placed in an ultra–sling for 4 weeks before physical therapy. We allowed light strengthening at 8 weeks, full strengthening at 12 weeks, and estimated return to sport at 4 months. Results: At 6 months postoperatively, the patient has regained symmetric motion, full strength, and has no residual pain or instability. Conclusion: Gross posterior instability is a rare and difficult condition to diagnose and manage. If no significant labral injuries are identified, injury to the posterior capsule must be considered and full assessment should be done when visualizing from the anterior portal. Repair of the posterior capsule is necessary and can be achieved all arthroscopically with this technique.

Interlinked Hamstrings for Combined Anterolateral and Anterior Cruciate Ligament Reconstruction: A Novel Technique for ALL.

Anterolateral ligament (ALL) reconstruction provides rotational stability in patients undergoing anterior cruciate ligament (ACL) reconstruction. The aim of this study was to assess the outcome of patients who underwent combined ACL and ALL reconstruction with a novel anatomic technique using hamstring tendon autograft and fixed loop suspensory device. From 2016 to 2018, 25 patients who underwent combined reconstruction of ACL and ALL in our Institution were evaluated retrospectively. International Knee Documentation Committee (IKDC) Score, Tegner Lysholm Knee Score, grade of pivot shift was assessed at a final follow-up. Mean follow-up was 31.5months (28-42). Mean IKDC (81.5) and Tegner Lysholm (82.8) Knee Scores improved significantly at a final follow-up, with all knees demonstrating negative pivot shift. All patients had good outcomes at 2years follow-up with no graft failure and with no residual instability. ACL and ALL reconstruction using this technique described for the anterolateral instability of the knee was satisfactory in our patients. This technique is simple, easily reproducible and avoids additional implants for ALL in the tibia. IV.

A quantitative evaluation of the individual components contributing to the functional ankle instability in patients with modified Broström procedure

Residual functional ankle instability regardless of the restoration of mechanical stability after the lateral ligament repair or reconstruction can cause recurrent sprain. The purpose of this study was to identify the sequential changes of joint-position sense, peroneal strength, postural control, and functional performance ability after the modified Broström procedure (MBP) for chronic ankle instability. A total of 46 patients (46 ankles) underwent the MBP for chronic ankle instability were eligible for this study and were followed for 1 year postoperatively. The changes of joint-position sense and peroneal strength were periodically evaluated with an isokinetic dynamometer. Postural control ability was evaluated using a one-leg stance test with eyes closed. The functional performance ability examination comprised a one-leg hop test, a 6-meter hop test, and a cross 3-meter hop test. The error in joint-position sense significantly improved from a mean 4.3º to 2.8º (p < .001). Peak torque for eversion significantly improved from a mean 18.2 Nm to 21.2 Nm (p = .024). Balance retention time significantly improved from a mean 4.7 seconds to 6.4 seconds (p < .001). Among the functional performance tests, only the one-leg hop test showed a significant improvement postoperatively (p = .031). At 1 year postoperatively, the recovery ratios compared to the unaffected ankle were 67.9% in joint-position sense (p < .001), 86.9% in peroneal strength (p = .012), and 74.4% in postural control (p < .001) with significant side-to-side differences. Although joint-position sense, peroneal strength, postural control, and functional performance ability were significantly improved after the MBP, recovery ratios compared to the unaffected ankle were insufficient up to 1 year postoperatively.

Total Knee Arthroplasty Conversion after Open-wedge High Tibial Osteotomy

Background: Open-wedge High Tibial Osteotomy (HTO) is an effective treatment for Osteoarthritis (OA) of the knee; however, postoperative changes due to HTO can make subsequent Total Knee Arthroplasty (TKA) technically difficult and can affect long-term survival. Case Report: Medio-lateral stability along with balanced flexion and extension gaps provides a good functional outcome. A 71-year-old man underwent TKA conversion after open-wedge HTO 12 years earlier; the conversion was performed due to arthritic deterioration in the knee. Medial instability was noted because of poor ligament balancing. The residual medial instability was managed with a knee brace due to the unavailability of the constrained prosthesis. Management of persistent mediolateral instability persisting after soft tissue release and balancing ideally requires varus-valgus constraint. Conclusion: TKA conversion after open-wedge HTO requires a special technique and careful preparation before surgery.

Complications of surgical reconstruction of multiligament injuries of the knee joint: diagnosis, prevention and treatment.

The main complications of surgical reconstruction of multiligament injuries of the knee joint are residual or recurrent instability, arthrofibrosis, popliteal artery injury, common peroneal nerve injury, compartment syndrome, fluid extravasation, symptomatic heterotopic ossification, wound problems and infection, deep venous thrombosis, and revision surgery.Careful surgical planning and execution of the primary surgical reconstruction of multiligament injuries of the knee joint can minimize the risk of the aforementioned complications.Careful postoperative follow-up is required to detect complications. Early recognition and prompt treatment are of paramount importance.To obtain good results in the revision surgery of failed multiligamentary knee reconstructions, it is crucial to perform a thorough and exhaustive evaluation to detect all the causes of failure.Addressing all associated injuries during revision surgery will lead to the best possible subjective and objective results, although functional outcomes are often modest.However, advanced age and high-energy injuries have been associated with the poorest functional outcomes after revision surgery of failed multiligament injuries of the knee joint. Cite this article: EFORT Open Rev 2021;6:973-981. DOI: 10.1302/2058-5241.6.210057

Second-look arthroscopy after double-bundle posterior cruciate ligament reconstruction: Effect of patient age

PurposeSecond-look arthroscopy is invasive but still one of the most useful postoperative evaluation methods since graft morphology including graft tension, graft tear, and synovial coverage can be directly evaluated. However, only a few studies have evaluated transplanted posterior cruciate ligament (PCL) grafts. This study aimed to clarify the PCL graft morphology and chondral damages at second-look arthroscopy after double-bundle PCL reconstruction (PCLR) and to investigate the effects of patient age on these arthroscopic findings. MethodsThis study retrospectively included 26 patients who underwent second-look arthroscopy at the time of hardware removal 14 months after double-bundle PCLR for isolated PCL injury from January 2007 to December 2020. The patients were divided into two groups: group A, 39 years or younger (n = 14); and group B, 40 years or older (n = 12). At second-look arthroscopy, the grafts were evaluated based on tension (taut, graft tension as tense as a normal PCL; lax, graft tension looser than a normal PCL, unclassified, completely torn graft), tear (one or more tendon strands torn), and synovial coverage (good, synovial coverage greater than 80% around the graft; fair, synovial coverage greater than 50%; and poor, synovial coverage less than 50%). The chondral damages were evaluated using the Outerbridge classification system. Radiographic posterior tibial translation with gravity sag view as well as clinical outcomes were also evaluated. ResultsAnterolateral (AL) graft tension was lax in 8% of the patients, whereas posteromedial (PM) graft tension was lax or unclassified in 24% (p = 0.043). Graft tear was observed only in the PM graft of 19% patients (p = 0.022). Synovial coverage of AL grafts was good or fair in all cases, whereas that of PM grafts was poor in 28% cases (p < 0.001). Regarding the effect of patient age, the synovial coverage of PM grafts was significantly poorer in group B (p = 0.033), but no statistical difference in graft tension or tear was found. The chondral damages were significantly advanced in group B (p ≤ 0.01), except for the trochlear groove and lateral femoral condyle. No patients had residual subjective posterior instability, knee swelling, or loss of extension exceeding 5° or flexion exceeding 10°. All patients had improved from grade II or III preoperatively to grade I or grade II in the posterior drawer test. The posterior tibial translation significantly improved from 10.0 ± 3.6 mm preoperatively to 3.6 ± 2.1 mm at second-look arthroscopy. No significant differences in the postoperative clinical outcomes were observed between the two groups. ConclusionThe morphology of the PM grafts at second-look arthroscopy after double-bundle PCLR was poorer than that of the AL grafts. Patient age negatively affected the postoperative graft synovial coverage and chondral status but did not affect the clinical outcomes.

Efficacy of Surgical Tenodesis for Treatment of Distal Semitendinosus Hamstring Tendon Injuries.

Background:Understanding the optimal management of distal semitendinosus hamstring injuries is critical for reducing pain, restoring preinjury function, maintaining knee stability, improving hamstring muscle strength, and minimizing the risk of complications and recurrence. To our knowledge, the outcomes of surgical tenodesis for distal semitendinosus hamstring injuries have not been previously reported.Hypothesis:Surgical tenodesis for injuries of the semitendinosus would enable return to preinjury level of sport with low risk of recurrence.Study Design:Case series; Level of evidence, 4.Methods:This prospective single-surgeon study included 13 professional athletes (12 men, 1 woman; mean age, 32 ± 8.2 years; mean body mass index, 26.7 ± 3.9 kg/m2) undergoing treatment for distal semitendinosus hamstring injuries with primary tenodesis to the distal semimembranosus. Indications for surgical tenodesis included distal semitendinosus tendon avulsion injury (n = 8) or residual tendon instability and hamstring weakness after semitendinosus graft harvest for anterior cruciate ligament reconstruction (n = 5). All study patients underwent a standardized postoperative rehabilitation program. The primary outcome was defined as time for return to sporting activity. Secondary outcomes were patient satisfaction, injury recurrence, and complications. The mean follow-up time was 17 months (range, 12-24 months) from date of surgery.Results:All study patients returned to their preinjury level of sporting activity. The mean time from the surgical intervention to return to full sporting activity was 15 ± 4.6 weeks. At 1-year follow-up, all study patients were still participating at their preinjury level of sporting activity, and 12 patients (92%) were very satisfied and 1 patient (8%) was satisfied about the outcomes of their surgery. No study patients had recurrence of the primary injury. No surgical complications, injury recurrence, or reoperations were observed within the follow-up period.Conclusion:Early return to sporting activity was seen after surgical tenodesis for distal semitendinosus hamstring injuries after acute trauma or residual symptoms following previous hamstring graft harvest, with high levels of patient satisfaction and low risk of recurrence at short-term follow-up.

Performance Characterization of ESA's Tropospheric Delay Calibration System for Advanced Radio Science Experiments

AbstractMedia propagation noises are amongst the main error sources of radiometric observables for deep space missions, with fluctuations of the tropospheric excess path length representing a relevant contributor to the Doppler noise budget. Microwave radiometers currently represent the most accurate instruments for the estimation of the tropospheric delay and delay rate along a slant direction. A prototype of a tropospheric delay calibration system (TDCS), using a 14 channel Ka/V band microwave radiometer, has been developed under a European Space Agency contract and installed at the deep space ground station in Malargüe, Argentina, in February 2019. After its commissioning, the TDCS has been involved in an extensive testbed campaign by recording a total of 44 tracking passes of the Gaia spacecraft, which were used to perform an orbit determination analysis. This work presents the first statistical characterization of the end‐to‐end performance of the TDCS prototype in an operational scenario. The results show that using TDCS‐based calibrations instead of the standard GNSS‐based calibrations leads to a significant reduction of the residual Doppler noise and instability.

Distal Radioulnar Joint, Distal Ulna Injury, and Lunate Facet Considerations in Distal Radius Fractures.

Injuries to the distal aspect of the ulna and the distal radioulnar joint (DRUJ) commonly occur concurrently with distal radius fractures. These fractures may also involve the sigmoid notch of the lunate facet of the radius. Each of these structures merits consideration when managing ulnar-sided injuries associated with distal radius fractures. Improper management of distal radioulnar complex injuries may result in limited wrist motion, persistent DRUJ instability, and pain despite successful fracture union. The distal ulna is the keystone of the distal radioulnar articulation. An understanding of the components of the distal radioulnar complex and methods to manage injuries of each of these components contributes to improved functional outcomes by restoring this keystone effect. The classification of distal radioulnar injuries discussed herein provides a framework for understanding the disruption of the ligamentous stabilizers of the DRUJ and identifying residual distal radioulnar instability after fracture fixation. Proper treatment of residual DRUJ instability will restore stability and minimize persistent functional impairment.

The changes of joint-position sense, peroneal strength, postural control, and functional performance ability after the modified Broström procedure for chronic ankle instability.

Purpose: Residual functional ankle instability regardless of the restoration of mechanical stability after the lateral ligament repair or reconstruction can cause recurrent sprain. The purpose of this study was to identify the sequential changes of joint-position sense, peroneal strength, postural control, and functional performance ability after the modified Broström procedure (MBP) for chronic ankle instability. Methods: A total of 46 patients (46 ankles) who underwent the MBP for chronic ankle instability were eligible for this study and were followed up for 1year postoperatively. The changes of joint-position sense and peroneal strength were periodically evaluated with an isokinetic dynamometer. Postural control ability was evaluated using a one-leg stance test with eyes closed. The functional performance ability examination comprised a one-leg hop test, a six-meter hop test, and a cross three-meter hop test. Results: The error in joint-position sense significantly improved from a mean 4.3° to 2.8° (p < 0.001). Peak torque for eversion significantly improved from a mean 18.2Nm to 21.2Nm (p = 0.024). Balance retention time significantly improved from a mean 4.7 s to 6.4 s (p < 0.001). Among the functional performance tests, only the one-leg hop test showed a significant improvement postoperatively (p = 0.031). At 1year postoperatively, the recovery ratios compared to the unaffected ankle were 67.9% in joint-position sense (p < 0.001), 86.9% in peroneal strength (p = 0.012), and 74.4% in postural control (p < 0.001), with significant side-to-side differences. Conclusion: Although joint-position sense, peroneal strength, postural control, and functional performance ability were significantly improved after the MBP, recovery ratios compared to the unaffected ankle were insufficient up to 1year postoperatively. Level of Evidence: Level IV (prospective case series).

Clinical Outcomes of Anterolateral Ligament Reconstruction or Lateral Extra-articular Tenodesis Combined With Primary ACL Reconstruction: A Systematic Review With Meta-analysis.

Background:Residual rotational instability after isolated anterior cruciate ligament reconstruction (ACLR) has been a challenge for many years. Anterolateral extra-articular procedures (AEAPs), including anterolateral ligament reconstruction (ALLR) or lateral extra-articular tenodesis (LET), are performed as a surgical option for additional rotational stability, but clear evidence for their usefulness is lacking.Purpose:To conduct a systematic review and meta-analysis of the literature regarding the efficacy of AEAP in primary ACLR.Study Design:Systematic review; Level of evidence, 3.Methods:A literature search, data extraction, and quality assessment were conducted by 2 independent reviewers. MEDLINE, EMBASE, and the Cochrane Library were searched in April 2020, following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A total of 3444 studies were screened, and 20 studies (11 randomized controlled trials and 9 nonrandomized studies) were evaluated. Functional outcomes, stability, and complications were compared between patients who underwent primary ACLR with AEAP and those who underwent isolated primary ACLR. For subgroup analysis, outcomes were compared according to AEAP technique (ALLR vs LET) and time from injury to surgery (≤12 vs >12 months). The methodological quality of the included studies was assessed using the Cochrane risk-of-bias tool, Jadad scale, and Newcastle-Ottawa Scale.Results:Compared with isolated ACLR, combined ACLR with AEAP led to improved pivot-shift grades and graft failure rates, regardless of the AEAP technique or of time from injury to surgery. A limited, marginal improvement in subjective function score was observed in patients who underwent AEAP combined with ACLR. In contrast to ALLR, patients who underwent LET combined with ACLR had an increased risk of knee stiffness and adverse events.Conclusion:Our review suggests that when there is a need to improve rotational stability and subjective function, AEAP combined with primary ACLR can be considered regardless of time from injury. ALLR appeared to be a better option for improving rotational stability compared with LET.