Leukocyte-Poor Platelet-Rich Plasma as a Treatment for Patellar Tendinopathy A Multicenter, Randomized Controlled Trial.

PURPOSE: The purpose of this study was to compare regimens of eccentric exercise and dry-needling, with and without an ultrasound-guided leukocyte-poor platelet-rich plasma (LP-PRP) injection, in patients with patellar tendinopathy. METHODS: Patients with symptomatic patellar tendinopathy based on physical examination and magnetic resonance imaging and who had failed at least 6 weeks of nonoperative treatment were enrolled and randomized at two centers to receive ultrasound-guided dry-needling (DN) alone or in addition to an injection of LP-PRP coupled with standardized eccentric strengthening exercises. Participants completed patient-reported outcome surveys at baseline and at 3, 6, 9, 12, and 26 weeks post-treatment. The primary outcome measure was the Victorian Institute of Sports Assessment (VISA) score for patellar tendinopathy (VISA-P) at 12 weeks, and secondary measures included the visual analog scale (VAS) for pain, Tegner activity scale, Lysholm knee scale (Lysholm), and Veterans Rand 12-Item Health Survey (VR12) questionnaire at 12 and 26 weeks. RESULTS: Thirty-one subjects were enrolled in the study (15 DN, 16 LP-PRP). Twenty-three patients were available for follow-up at all time points. There were no statistically significant differences between the two groups at baseline. At 12 weeks post-treatment, both the LP-PRP and DN groups demonstrated statistically significant (p < 0.05) improvements from baseline with respect to Lysholm score (34.5 ± 15.1 and 31.7 ± 18.4), VAS pain scale (-1.58 ± 2.1 and -2.8 ± 1.9, respectively), and VISA score (19.2 ± 15.9 and 28.4 ± 19.4, respectively). At 26 weeks post-treatment both groups demonstrated statistically significant (p < 0.05) improvements in Lysholm score (23.6 ± 23.1 and 24.5 ± 17.3, respectively) and VAS pain score (-1.67 ± 2.3 and -2.18 ± 2.9, respectively). The LP-PRP group failed to show significance for VISA-P score from 0 to 26 weeks, though the DN group did (22.0 ± 14.6). There were no statistically significant differences between the two groups in mean VISA, VAS, Lysholm, or the Short Form Health Survey (SF-12) scores at either the 12 week or 26-week follow-up time points. CONCLUSION: The results of the current study demonstrate that both DN and DN plus LP-PRP are effective treatment options in the management of symptomatic patellar tendinopathy, however, LP-PRP did not add any additional improvement over DN alone.

The Impact of Adding a Tibial Tubercle Osteotomy to Medial Patellofemoral Ligament Reconstruction in the Treatment of Patellar Instability.

BACKGROUND: An isolated medial patellofemoral ligament (MPFL) reconstruction (MPFLR) has been demonstrated to be an effective treatment option in the prevention of patellar instability, but there is growing support for performing a tibial tubercle osteotomy (TTO) in patients with an elevated tibial tubercle-trochlear groove distance. The purpose of this study was to evaluate the impact of adding a TTO to MPFLR on patient reported outcomes. METHODS: A retrospective review of patients who underwent MPFLR with or without TTO with a minimum of 12-month follow-up was performed. Patients in both groups were matched based on age, sex, and follow-up time. Recurrent instability (including re-dislocation and subluxation), visual analog scale (VAS) for pain score, Kujala score, and satisfaction were evaluated. RESULTS: There were 59 patients who underwent MPFLR with concomitant TTO performed at our institution and met our inclusion and exclusion criteria. These patients were then matched to patients undergoing isolated MPFLR based on demographics and follow-up time. The mean age was 25.0, 76.3% were female, and the mean follow-up time was 49 months. There was a significant difference in mean tibial tubercle-trochlear groove distance (19.8 ± 3.9 vs. 14.1 ± 2.8) between groups. There was no significant difference in VAS (1.48 ± 2.0 vs. 1.49 ± 2.1, p = 0.972), satisfaction (86.1% ± 24.2% vs. 81.2% ± 27.9, p = 0.311), or revision surgeries (10.2% vs. 10.2%) between groups. CONCLUSION: There was a low complication rate, excellent patient reported outcomes, and a low rate of recurrent patellar instability following TTO and MPFLR with allograft.

The Functional Organization of Corticomotor Neurons Within the Motor Cortex Differs Among Basketball and Volleyball Athletes With Patellar Tendinopathy Compared to Asymptomatic Controls.

Patellar tendinopathy (PT) typically affects jumping-sport athletes with functional impairments frequently observed. Alterations to the functional organization of corticomotor neurons within the motor cortex that project to working muscles are evident in some musculoskeletal conditions and linked to functional impairments. We aimed to determine if functional organization of corticomotor neuron projections differs between athletes with PT and asymptomatic controls, and if organization is associated with neuromuscular control. We used a cross-sectional design, and the setting was Monash Biomedical Imaging. Basketball and volleyball athletes with (n = 8) and without PT (n = 8) completed knee extension and ankle dorsiflexion force matching tasks while undergoing fMRI. We determined functional organization via identification of the location of peak corticomotor neuron activation during respective tasks (expressed in X, Y, and Z coordinates) and calculated force matching accuracy for both tasks to quantify neuromuscular control. We observed significant interactions between group and coordinate plane for functional organization of corticomotor projections to knee extensors (p < 0.001) and ankle dorsiflexors (p = 0.016). Compared to controls, PT group peak corticomotor activation during the knee extension task was 9.6 mm medial (p < 0.001) and 5.2 mm posterior (p = 0.036), and during the ankle dorsiflexion task 8.2 mm inferior (p = 0.024). In the PT group, more posterior Y coordinate peak activation location during the knee extension task was associated with greater task accuracy (r = 0.749, p = 0.034). Functional organization of corticomotor neurons differed in jumping athletes with PT compared to controls. Links between functional organization and neuromuscular control in the PT group suggest organizational differences may be relevant to knee extension neuromuscular control preservation.

Bilateral fracture of anterior tibial tuberosity with complete patellar tendon rupture in an adolescent patient.

Anterior tibial tuberosity fracture avulsion is an uncommon injury. A concomitant patellar rupture is even more scarcely encountered. We report the case of a 14-year-old male patient who suffered bilateral anterior tuberosity fractures with concomitant bilateral complete patellar tendon rupture. Adolescence, athletic activity, and high BMI may have contributed to this concomitant bilateral injury. Both lesions were treated in a one-stage repair surgery, performing an open reduction and internal fixation of the tibial tuberosity with a cannulated cortical screw and a primary tendon suture following the Krakow technique. To the authors' knowledge, no other cases of bilateral presentation of both lesions have been reported so far in the literature.

Reduced Knee Flexion Strength 18 Years After ACL Reconstruction With Hamstring Tendon Versus Patellar Tendon.

BACKGROUND: Bone-patellar tendon-bone (BPTB) and double-looped semitendinosus and gracilis (hamstring) grafts are commonly used for anterior cruciate ligament (ACL) reconstruction. Short-term and midterm studies show little or no differences between the 2 grafts; however, there are only a few long-term studies to compare results between the 2 grafts. PURPOSE: To compare the results after using either BPTB grafts or hamstring tendon grafts 18 years after ACL reconstruction. STUDY DESIGN: Randomized controlled trial; Level of evidence 2. METHODS: A total of 114 patients with ACL rupture between 2001 and 2004 were randomized to reconstruction with either a BPTB graft or a hamstring tendon graft. Patients were operated on at 4 major hospitals. The 18-year follow-up evaluation included anterior knee laxity measured with a KT-1000 arthrometer, defined as the primary outcome, while clinical examination (Lachman and pivot-shift tests), isokinetic testing of muscle strength, patient-reported outcome measures, and an assessment of radiographic osteoarthritis using the Kellgren-Lawrence classification were defined as secondary outcomes. RESULTS: A total of 96 patients (84%, 47 BPTB and 49 hamstring grafts) were available for follow-up, 71 of these for clinical examination. Seven of 96 patients were excluded for ACL revision (n = 5) or knee replacement (n = 2) surgery. In total, 25 patients (10 BPTB and 15 hamstring grafts) had undergone additional surgery other than ACL revision or total knee arthroplasty. There were no significant differences between the groups in terms of anterior laxity test with KT-1000 arthrometer (primary outcome). In secondary outcomes, no significant differences between groups were reported regarding clinical examination, patient-reported outcome scores, or radiographic osteoarthritis (Kellgren-Lawrence grade 2-4 for patellofemoral joint [18 hamstring and 14 BPTB] or tibiofemoral joint [20 hamstring and 19 BPTB]), while isokinetic testing revealed that the hamstring group had a 10.7% reduction in mean peak flexion torque compared with the BPTB group at 60 deg/s (df = 59; P = .011). At 60 deg/s the mean total flexion work in the hamstring group was reduced by 17.2% compared with the BPTB group (df = 59; P = .002). CONCLUSION: The flexion strength in the hamstring group was significantly reduced in the operated knee after 18 years. There were no significant differences between the groups regarding subjective outcomes, patient-reported outcomes, range of motion, clinical and instrumented knee laxity, and the development of osteoarthritis. REGISTRATION: NCT05876013 (ClinicalTrials.gov identifier).

Mechanical properties of the patellar tendon in weightlifting athletes - the utility of myotonometry. Adaptations of patellar tendon to mechanical loading.

Purpose: Tendons adapt to loads applied to them, by changing their own mechanical properties. The purpose of the study was to examine the influence of practicing sport in the form of weightlifting/strength training by individuals of various age groups upon the mechanical properties of the patellar tendon. Methods: 200 people participated in the study. Group 1 (n = 109) comprised individuals training strength sports as amateurs, group 2 (n = 91) consisted of people who were not physically active. The patellar tendon was examined in various positions of the knee joint: 0, 30, 60, 90, 120° respectively. The following mechanical parameters were measured with the use of a device for myoto-nometric measurements, MyotonPRO: frequency [Hz], stiffness [N/m], decrement [log], relaxation time [ms] and creep [De]. The results were compared as regards physical activity, training history, BMI value, and gender. Results: Stiffness and tone increased while elasticity decreased with patellar tendon stretching degree. In the group of individuals in training, greater stiffness and tone and lower elasticity were noted. Moreover, stiffness and tone appeared to be higher in elderly people and individuals with longer training experience. Conclusions: Mechanical loads connected with strength training result in development of adaptive changes in the patellar tendon, in the form of higher stiffness and tone, as well as lower elasticity. The MyotonPRO device is useful for quantitative assessment of the mechanical properties of patellar tendon.

Comparison of a handheld ultrasound device with cart-based ultrasound for the assessment of gout lesions in people with established gout.

OBJECTIVES: Use of handheld portable ultrasound is increasing and would improve access for people with rheumatic disease when conventional, cart-based ultrasound is unavailable. This study compared handheld and cart-based ultrasound for the assessment of gout lesions in people with gout. METHODS: The lower limbs of 21 participants with gout were independently scanned at six sites (1st and 2nd metatarsophalangeal joints, knee, patellar ligament, Achilles tendon, and peroneal tendons) using cart-based (LOGIQ P9) and handheld (Vscan Air™) ultrasound by two rheumatologists. One rheumatologist was randomized to scan the right or left leg first with the cart-based or handheld ultrasound. The other rheumatologist scanned the legs in the opposite order with the imaging devices reversed. Images were saved and blinded images scored for double contour, tophus, erosion and aggregates using OMERACT definitions by two rheumatologists experienced in gout ultrasound. RESULTS: On handheld ultrasound, 90% of participants had at least one site with double contour, tophus and erosions, and 100% had at least one site with aggregates. There were similar findings using cart-based ultrasound. However, site-level inter-device analysis showed only fair-good agreement: kappa (percentage agreement) for double contour 0.22 (67%), tophus 0.46 (77%), erosion 0.63 (83%) and aggregates 0.37 (75%). There were more aggregates detected by cart-based ultrasound in joints and more tophi detected by handheld ultrasound in ligaments and tendons. CONCLUSIONS: Handheld ultrasound can detect gout lesions in people with established gout. However, concordance between cart-based and handheld ultrasound in detection of some gout lesions is low, particularly double contour and aggregates.

Muscle and tendon morphology of a world strongman and deadlift champion.

This study compared the muscle and tendon morphology of an extraordinarily strong individual, a World's Strongest Man and deadlift champion (WSM), with that of various other athletic, trained, and untrained populations. The WSM completed the following: 1) 3.0-T MRI scans, to determine the volume of 22 individual lower limb muscles, 5 functional muscle groups, patellar tendon (PT) cross-sectional area (CSA), and PT moment arm; and 2) countermovement jumps (CMJ) and isometric midthigh pull (IMTP) contractions. The WSM was compared with previously assessed groups from our laboratory (muscle and tendon) and the wider research literature (CMJ and IMTP). The WSM's CMJ peak power (9,866 W) and gross (9,171 N) and net (7,480 N) IMTP peak forces were higher than any previously published values. The WSM's overall measured leg muscle volume was approximately twice that of untrained controls (+96%) but with pronounced anatomical variability in the extent of muscular development. The plantar flexor group (+120%) and the guy rope muscles (sartorius, gracilis, and semitendinosus: +140% to +202%), which stabilize the pelvis and femur, demonstrated the largest differences relative to that of untrained controls. The WSM's pronounced quadriceps size (greater than or equal to twofold vs. untrained) was accompanied by modest PT moment arm differences and, notably, was not matched by an equivalent difference in PT CSA (+30%). These results provide novel insight into the musculotendinous characteristics of an extraordinarily strong individual, which may be toward the upper limit of human variation, such that the WSM's very pronounced lower limb muscularity also exhibited distinct anatomical variability and with muscle size largely uncoupled from tendon size.NEW & NOTEWORTHY Lower-body muscle size of an extraordinarily strong individual, a World's Strongest Man and deadlift champion (WSM), was approximately twice that of controls but was underpinned by pronounced anatomical variability in the extent of muscular development (+23-202%): the plantar flexor group and guy rope muscles demonstrating the largest differences. The WSM's quadriceps size (more than or equal to twice that of controls) contrasted with modest differences in patella tendon moment arm (+18%) and was uncoupled from patellar tendon size (+30%).

Re-revision Extensor Mechanism Reconstruction Because of Nonunion and Tendon Failure After Total Knee Arthroplasty.

Extensor mechanism (EM) disruption after total knee arthroplasty (TKA) is devastating, especially in cases of re-rupture. A 67-year-old man with diabetes had patellar tendon rupture after revision TKA and then had migration of the bone block after Achilles tendon allograft with bone block (ATBB) augmentation with cerclage. A third reconstruction was performed with open reduction and internal fixation and high-strength braided suture augmentation. Five months postoperatively, the patient had regained full range of motion with intact EM and hardware. The risk of re-rupture is high in ATBB, and the primary issues in this case were nonunion and tendinous compromise. A construct that encompasses compression and buttressing of the bone block with tendon augmentation potentially addresses the risks of recurrent EM rupture in more complex cases. [Orthopedics. 2024;47(5):e273-e276.].

Location of Measurement Matters: Unveiling Regional Dynamics and Sex Differences in Patellar Tendon Strain In Vivo.

Patellar tendinopathy is more prevalent in males versus female athletes and commonly presents in the medial region of the tendon. Separate measures of patellar tendon strain in the medial, central, and lateral regions of the tendon, however, have not been quantified. The purpose was to investigate the differences in tendon strain between the medial, lateral, and central regions of the patellar tendon in healthy men and women. Strain in the medial and lateral regions of the patellar tendon in healthy participants (10 males, 10 females) was evaluated using ultrasound during isometric quadriceps contractions at 20%, 40%, 60%, 80%, and 100% of maximum voluntary contraction (MVIC) in 60° and 90° of knee flexion. Central strain was also measured at 60% MVIC in 90° of knee flexion. Mixed models were used to determine strain between tendon regions and sex at 60% MVIC in 90° of knee flexion. Sequential modeling was used to fit region, sex, %MVIC, and angle to predict strain. The central region had less strain compared with both medial and lateral regions. The lateral region had higher strain compared with the medial region regardless of sex. Females had higher strain compared with males, regardless of region. Knee position did not influence tendon strain. Patellar tendon strain differs by region and sex. The varying prevalence between sex and in location of patellar tendinopathy may in part be explained by the unbalanced strains. Differential assessment of regional patellar tendon strain may be of importance for understanding injury risk and recovery with exercise.

Results of medial patellofemoral ligament reconstruction with and without tibial tubercle osteotomy in patellar instability: a systematic review and single-arm meta-analysis.

PURPOSE: To confirm which method provides lower rate of recurrent instability and superior clinical outcomes. METHOD: We searched PubMed, Embase and Web of Science for the trials involving one intervention or both for patellar instability: medial patellofemoral ligament reconstruction (MPFLR) with and without tibial tubercle osteotomy (TTO). The postoperative Kujala score, Lysholm score, Tegner scores and the rate of recurrent instability (dislocation or subluxation) were analyzed as the primary clinical outcome parameters in a random or fixed effects meta-analysis. RESULTS: In total, 43 articles met inclusion criteria after full-text review. A total of 2046 patients were analyzed. The overall mean age was 20.3 years (range, 9.5-60.0 years), with a mean follow-up time of 3.2 years (range, 1-8 years). The mean Kujala scores in MPFLR and MPFLR + TTO were 89.04 and 84.44, respectively. There was significant difference in Kujala scores between MPFLR and MPFLR + TTO (MD = 4.60, 95%CI: 1.07-8.13; P = 0.01). The mean Lysholm scores in MPFLR and MPFLR + TTO were 90.59 and 88.14, respectively. There was no significant difference in Lysholm scores between MPFLR and MPFLR + TTO (MD = 2.45, 95%CI: -3.20-8.10; P = 0.40). The mean Tegner scores in MPFLR and MPFLR + TTO were 5.30 and 4.88, respectively. There was no significant difference in Tegner scores between MPFLR and MPFLR + TTO (MD = 0.42, 95%CI: -0.39-1.23; P = 0.31). At final follow-up, the rates of recurrent instability in MPFLR and MPFLR + TTO were 3% and 4%, respectively. There was no significant difference in the rates between MPFLR and MPFLR + TTO (OR = 0.99, 95%CI: 0.96-1.02; P = 0.4848). CONCLUSION: MPFLR and MPFLR + TTO are effective and reliable treatments in the setting of patellofemoral instability. MPFLR seems to show a better performance in functional outcomes than MPFLR + TTO. Moreover, their rates of recurrent instability are very low, and no significant difference exists.

Functionality and jump performance in patellar tendinopathy with the application of three different treatments.

OBJECTIVES: The aim is to assess performance characteristics in jumps and functionality in participants with patellar tendinopathy and compare changes with various tendinopathy treatments in the short and medium term. As a secondary objective, the study aims to verify the relationship between changes in knee functionality assessed by the VISA-P and jump capacity in the different treatment groups. DESIGN: A double-blinded randomized controlled trial. METHODS: Recruitment was conducted at sport clubs, with 48 participants with patellar tendinopathy included in the study. Participants were randomized into groups: dry needling (DN), percutaneous electrolysis (PNE), and sham needling as the control group (CG), all combined with eccentric exercise (EE). Functionality and performance during jumps, including squat jump (SJ) and counter movement jump (CMJ), were assessed. RESULTS: Significant differences were found in functionality between the pre-test and post-test evaluations, as well as between the pre-test and follow-up evaluations, in all three groups (p < 0.001). The DN group experienced an improvement in eccentric power (p = 0.021). A moderate correlation was found between the pre-test and post-test changes in functionality and SJ maximum concentric force (r = 0.63, p < 0.01, CI: 0.1; 0.8), CMJ maximum concentric force (r = 0.52, p = 0.05, CI: -0.01; 0.8), and CMJ eccentric power in the DN group (r = 0.63, p = 0.01, CI: 0.1; 0.8). CONCLUSIONS: Eccentric exercise could be effective in improving functionality in patellar tendinopathy and DN could improve eccentric power in jumps performance. Moreover, the DN group experienced an increase in functionality that correlated with the improvements found in jump performance in eccentric power and concentric strength.

Anatomical medial patellofemoral ligament reconstruction improves sport participation and activity levels in adolescents with recurrent patellar dislocation.

OBJECTIVES: This study aims to evaluate the clinical outcomes of an anatomical medial patellofemoral ligament (MPFL) reconstruction and the effects of concomitant patellofemoral joint injuries and radiological findings on outcomes in adolescents with recurrent patellar dislocation (RPD). PATIENTS AND METHODS: Between January 2011 and January 2020, a total of 34 patients (19 males, 15 females; median age: 15.6 years; range, 13 to 17 years) with RPD who underwent anatomic MPFL reconstruction were retrospectively analyzed. Lateral release was performed as indicated. Clinical outcomes were evaluated preoperatively and at the final follow-up using the Visual Analog Scale (VAS), Lysholm, Kujala, and Tegner activity rating scales. Magnetic resonance imaging was performed to detect concomitant injuries such as bone, cartilage, and soft tissue injuries. RESULTS: The mean follow-up was 5±2 years. All postoperative knee functions and activity levels were statistically significantly improved without re-dislocation (p<0.001). There was no statistically significant relationship between the presence and location of cartilage lesions and clinical outcomes (p>0.05). Patients with cartilage lesions had a significantly higher CatonDeschamps index and a higher incidence of bone edema in both the patella and femur than patients without. CONCLUSION: Anatomic MPFL reconstruction with meticulous physical therapy has successful clinical outcomes, prevents re-dislocation, and increases participation in sports and activity levels in adolescent patients with RPD. Although cartilage injuries are common after RPD, it has no adverse effect on clinical outcomes in the mid-term.

Gauging force by tapping tendons? Inaccurately in the human patellar tendon.

Accurately estimating in vivo tendon load non-invasively remains a major challenge in biomechanics, which might be overcome by shear-wave tensiometry. Shear-wave tensiometry measures the speed of mechanically induced tendon shear waves by skin-mounted accelerometers. To gauge the feasibility and accuracy of this novel technique, we obtained patellar tendon shear wave speeds via shear-wave tensiometry during sustained or ramp voluntary contractions of the knee extensors in two experiments (n = 8 in both). In experiment one, participants produced a constant knee extension torque of âˆ¼ 50 Nm at five different knee joint angles (i.e. variable tendon load), which resulted in estimated patellar tendon forces between 1005 ± 6N and 1182 ± 16 N. However, wave speed squared did not correlate with estimated tendon force within participants (rrm(31) = -0.19, p = 0.278). In experiment two, averaged correlation coefficients between normalized wave speed squared and torque of maximal and submaximal voluntary contractions across participants ranged between r = 0.43 and r = 0.94, while the time-varying correlation between these normalized signals ranged from r = -0.99 to r = 1.00. Further, the mean absolute errors (MAEs) between normalized wave speed squared and normalized torque across participants ranged between 0.03 and 0.54, which were larger than the MAEs between normalized torque and normalized summed EMG amplitude from the superficial quadriceps muscles (0.03-0.54 versus 0.06-0.26, respectively). In conclusion, there was no simple relation between shear wave speed squared and patellar tendon load, which severely limits the feasibility of shear-wave tensiometry for accurately estimating in vivo tendon load at the knee joint.

Effect of a single versus serial platelet-rich plasma injection on the healing of acute patellar tendon defect: an experimental study.

BACKGROUND: There is no consensus on the frequency and timing of platelet-rich plasma (PRP) injection in tendon healing. We aimed to evaluate the effectiveness of single versus multiple PRP injections in the healing of patellar tendon defects in the experimental model, through histological and biomechanical investigation. METHODS: Forty-four male skeletally mature Dutch rabbits were randomly divided into the five study groups ( A, B,C, D,E). After creating a longitudinal acute patellar tendon defect on both knees (One-third the width of the patella tendon), the right legs of the rabbits were used as the intervention group and the left legs as the control groups. Animals in groups A, B, and C were euthanized on days 7, 14, and 28, respectively, after the first PRP injection. Animals in group D received the second PRP injection on day 10 and was euthanized on day 14. Animals in group D received the second and third PRP injections on days 10 and 20, respectively, and were euthanized on day 28. The outcomes were evaluated histologically (modification of Movin's Grading) and biomechanically. RESULTS: The inflammatory condition was exaggerated in groups D and E. Load at failure was higher in the non-injected side of groups D and E, while there was no significant difference between the right and left legs of the three groups A, B and C. In other word, groups with a single PRP injection were more resistant to the increasing load compared to the groups with multiple PRP injections. CONCLUSIONS: PRP improves tendon healing if injected early after injury, while its injection after the initial phase of injury hampers tendon healing. In addition, a single PRP injection seems to be more effective than multiple PRP injection. Therefore, in cases where PRP injection is indicated for tendon repair, such as acute tendon injury, we recommend using a single PRP injection during tendon repair surgery.

Treatment outcome of chronic patellar tendon rupture using autogenous semitendinosus graft: a retrospective case series.

PURPOSE: This study highlights the pattern of presentation, treatment, early functional outcome, and complications observed in the management of chronic patellar tendon ruptures using our preferred technique of autogenous semitendinosus graft reconstruction. METHODS: This was a retrospective case series involving consecutive patients who underwent patellar tendon reconstruction and met the inclusion criteria. The outcome measures were determined by the post-operative knee range of motion (R.O.M), the post-operative International Knee Documentation Committee (IKDC) score, and pattern of post-operative complications. RESULTS: Nine patients were included in this case series. The mean age of the patients was 35.4 ± 6.8 years (range 27-44 years). Trauma to the knee accounted for majority of the cases (62.5%). Six (66.7%) of the nine patients suffered a patellar tendon rupture from contact injury during sporting activities. The mean length of time from injury to presentation was 20.5 ± 11.2 weeks (range 6-69.5 weeks). Normal knee function in a case (11.1%), nearly normal knee function in 7 cases (77.8%), and abnormal knee function in a case (11.1%) were recorded as a measure of outcome of surgery. The mean post-operative IKDC score was 70.0 ± 6.1 (range 55-77), which was higher than the mean pre-operative score of 26.4 ± 5.1 (range 18-32). The post-operative knee R.O.M averaged 97.2 ± 16.2° (range 70-120°) with a single case with a 10° extension lag noted. CONCLUSION: Normal to near-normal knee function was obtained with the treatment of chronic patellar tendon rupture in the majority of cases using autogenous semitendinosus graft for patellar tendon reconstruction in our series.

Arthroscopic medial patellofemoral ligament reconstruction with polyethylene suture combined with medial retinaculum plication for the treatment of acute patellar dislocation in young and middle-aged patients with a follow-up of at least 2 years.

PURPOSE: The purpose of this study was to propose a surgical technique for arthroscopic medial patellofemoral ligament (MPFL) reconstruction with polyethylene suture combined with medial retinaculum plication and to evaluate the efficacy of this surgical technique in the treatment of acute patellar dislocation. METHODS: Clinical data of patients with acute patellar dislocations treated with arthroscopic MPFL reconstruction with polyethylene tape (FiberTape) combined with medial support band compression were analyzed retrospectively from January 2018 to January 2021. The mean age of the patients was 25.15 ± 4.66 years; the mean follow-up time was 27.5 (24-36) months. Clinical evaluation consisted of apprehension test results, patellar extrapolation test results, Lysholm score, Kujala score, and IKDC score, the Patellar lateral shift distance and patellar tilt angle (PTA) measured by CT scan. RESULTS: All patients had no recurrent patellar dislocation or subluxation after surgery, and the apprehension test was negative. In all patients, the Kujala score (36.0 ± 9.9 vs. 98.2 ± 3.1), the IKDC score (48.6 ± 7.0 vs. 90.6 ± 4.4) and the Lysholm score (32.8 ± 10.4 vs. 96.7 ± 3.1) had improved at the 24-month follow up (P < 0.05). In addition, PTA was significantly lower at the 12-month follow-up and 24-giving-month follow-up compared to the preoperative period (P < 0.05, Table 2). The patellar lateral shift distance decreased from 14.94 ± 6.11 mm preoperatively to 3.00 ± 1.40 mm (12-month follow up) and 3.26 ± 1.37 mm (24-month follow up), respectively. CONCLUSION: Arthroscopic MPFL reconstruction with polyethylene suture combined with medial retinaculum plication is a safe and reliable surgical technique for the treatment of acute patellar dislocation in young and middle-aged patients. LEVEL OF EVIDENCE: Level III, Therapeutic Study.

Discipline-specific Torque-Velocity Profiles and Musculotendinous Morphology in Athletes.

OBJECTIVES: The aim of this study was to compare torque-velocity profiles, muscle architecture, tendon dimensions, and bilateral-symmetry between competitive cyclists (CY), competitive runners (RN), ice-hockey players (IH), basketball players (BP), and physically-active individuals (CN) (n=10 for each group). METHODS: Vastus lateralis (VL) muscle and patellar tendon (PT) structures were determined with B-mode ultrasonography, and maximal knee extensor isokinetic torque was assessed at three different velocities. RESULTS: Optimal torque and velocity were lower in runners than CY, BP and IH (p<0.05). Maximal power was similar between the athlete groups but greater than CN (p<0.05). Furthermore, RN and BP reached their peak-torque at longer muscle lengths compared to IH and CY (p<0.05). RN had the lowest VL muscle thickness and the greatest fascicle length, while CY had the greatest pennation angle (p<0.05). CY had the greatest PT thickness, particularly at the proximal and medial sites, while BP at the distal point (p<0.05), with similar trends observed for PT cross-sectional-area. CONCLUSIONS: Our findings show that even if power generating capacity is similar between athletic disciplines, there are discipline-specific muscle adaptations, where particularly runners appear to have muscles adapted for speed rather than torque development, while in cyclists, velocity is sacrificed for torque development.