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.

Tendon Healing in a Mouse Model of Loeys-Dietz Syndrome: Controlled Study Using a Patellar Tendon Transection Model.

BACKGROUND: Loeys-Dietz syndrome (LDS) is a rare autosomal-dominant connective tissue disorder caused by genetic mutations in the transforming growth factor-ß (TGFß) signaling pathway. In addition to vascular malformations, patients with LDS commonly present with bone and tendon abnormalities, including joint laxity. While TGFß signaling dysregulation has been implicated in many of these clinical manifestations, the degree to which it influences the tendinopathy and tendon healing issues in LDS has not been determined. METHODS: Wound healing after patellar tendon transection was compared between wild-type (WT) and Tgfbr2-mutant (LDS) mice (7 mice per group). In all mice, the right patellar tendon was transected at midsubstance, while the left was untouched to serve as a control. Mice were euthanized 6 weeks after surgery. Tendon specimens were harvested for histopathologic grading according to a previously validated scoring metric, and gene expression levels of Mmp2, Tgfb2, and other TGFß-signaling genes were assayed. Between-group comparisons were made using 1-way analysis of variance with post hoc Tukey honestly significant difference testing. RESULTS: Expression levels of assayed genes were similar between LDS and WT tendons at baseline; however, at 6 weeks after patellar tendon transection, LDS tendons showed sustained elevations in Mmp2 and Tgfb2 compared with baseline values; these elevations were not seen in normal tendons undergoing the same treatments. Histologically, untreated LDS tendons had significantly greater cellularity and cell rounding compared with untreated WT tendons, and both WT and LDS tendons had significantly worse histologic scores after surgery. CONCLUSION: We present the first mechanistic insight into the effect of LDS on tendons and tendon healing. The morphologic differences between LDS and WT tendons at baseline may help explain the increased risk of tendon/ligament dysfunction in patients with LDS, and the differential healing response to injury in LDS may account for the delayed healing and weaker repair tissue. LEVEL OF EVIDENCE: Level V.

A Comparative Study of Treatment Interventions for Patellar Tendinopathy: A Randomized Controlled Trial.

OBJECTIVES: To determine the additional effect of dry needling (DN) or percutaneous needle electrolysis (PNE) combined with eccentric exercise (EE) and determine which is the most effective for patients with patellar tendinopathy (PT). DESIGN: Blinded, randomized controlled trial, with follow-up at 10 and 22 weeks. SETTINGS: Recruitment was performed in sport clubs. Diagnosis and intervention were conducted at San Jorge University. PARTICIPANTS: Patients (N=48) with PT with pain for at least 3 months between the ages of 18 and 45 years. INTERVENTIONS: Three interventions were carried out: DN and EE, PNE and EE, and EE with sham needle as the control group. MAIN OUTCOME MEASURES: Disability was measured using the Victorian Institute of Sports Assessment Questionnaire, patellar tendon. Visual analog scale was used to measure pain over time, the Short Form-36 was used to measure quality of life, and ultrasound was used to measure structural abnormalities. RESULTS: A total of 48 participants (42 men, 6 women; average age, 32.46y; SD, 7.14y) were enrolled. The improvement in disability and pain in each group between baseline and post-treatment and baseline and follow-up was significant (P≤.05), without differences among groups. CONCLUSION: DN or PNE combined with an EE program has not shown to be more effective than a program of only EE to improve disability and pain in patients with PT in the short (10wk) and medium (22wk) terms. Clinical improvements were not associated with structural changes in the tendon.

The quadriceps insertion of the medial patellofemoral complex demonstrates the greatest anisometry through flexion.

PURPOSE: A comprehensive understanding of the biomechanical properties of the medial patellofemoral complex (MPFC) is necessary when performing an MPFC reconstruction. How components of the MPFC change over the course of flexion can influence the surgeon's choice of location for graft fixation along the extensor mechanism. The purpose of this study was to (1) determine native MPFC length changes throughout a 90° arc using an anatomically based attachment and using Schöttle's point, and (2) compare native MPFC length changes with different MPFC attachment sites along the extensor mechanism. METHODS: Eight fresh-frozen (n = 8), cadaveric knees were dissected of all soft tissue structures except the MPFC. The distance between the femoral footprint (identified through anatomical landmarks and Schottle's point) and the MPFC was calculated at four attachment sites along the extensor mechanism [midpoint of the patella [MP], the center of the osseous footprint of the MPFC (FC), the superomedial corner of the patella at the quadriceps insertion (SM), and the proximal extent of the MPFC along the quadriceps tendon (QT)] at 0°, 20°, 40°, 60°, and 90° of flexion. RESULTS: Length changes were investigated between the MPFL femoral attachment site and the radiographic surrogate of the MPFL attachment site, Schottle's Point (SP). Paired t tests at each of the four components showed no differences in length change from 0° to 90° when comparing SP to the anatomic MPFC insertion. MPFL length changes from 0° to 90° were greatest at the QT point (13.9 ± 3.0 mm) and smallest at the MP point (2.7 ± 4.4 mm). The FC and SM points had a length change of 6.6 ± 4.2 and 9.0 ± 3.8, respectively. Finally, when examining how the length of the MPFC components changed through flexion, the greatest differences were seen at QT where all comparisons were significant (p < 0.01) except when comparing 0° vs 20° (n.s.). CONCLUSION: The MPFC demonstrates the most significant length changes between 0° and 20° of flexion, while more isometric behavior was seen during 20°-90°. The attachment points along the extensor mechanism demonstrate different length behaviors, where the more proximal components of the MPFC display greater anisometry through the arc of motion. When performing a proximal MPFC reconstruction, surgeons should expect increased length changes compared to reconstructions utilizing distal attachment sites.

The adaptation of sport assessment-patella questionnaire into simplified Chinese version: cross-cultural adaptation, reliability and validity.

BACKGROUND: The original version of Victorian Institute of Sport Assessment-Patella Questionnaire (VISA-P) is developed in English, and aimed to assess the severity of patellar tendinopathy symptoms. Before used in China, it should be translated to Chinese version. OBJECTIVES: Our aim is to make a translation/cross-culturally adaption for the VISA-P into simplified Chinese version (VISA-PC). And primarily validate the VISA-PC in Chinese speaking population. METHODS: The translation process of VISA-P questionnaire into simplified Chinese version (VISP-PC) followed the International recognized guideline. Cross-cultural adaptation was carried out with a clinical measurement study. A total of 128 projects which consisted 33 healthy students, 39 patients with patellar tendinopathy and 56 military students (receive military training as at-risk population) were included into this study. Internal consistency was evaluated with Cronbach's alpha, and test-retest reliability was assessed with intraclass correlation coefficients (ICCs). Construct validity and floor and ceiling effects were also tested. RESULTS: The scores were 95.84 ± 5.97 of healthy group, 91.87 ± 9.03 of at-risk group, 62.49 ± 11.39 of pathological group. There is no ceiling and floor effect of VISA-PC. The Cronbach's alpha (0.895) and ICC (0.986) values showed good internal consistency and reliability. There were high correlations between VISA-PC and Kujala patellofemoral score (r = 0.721). VISA-PC score also had good correlation with the relevant SF-36 items. CONCLUSION: The VISA-PC was well translated into simplified Chinese version (VISA-PC), which is reliable and valid for Chinese-speaking patients with patellar tendinopathy. LEVEL OF EVIDENCE: II.

Jump-landing mechanics in patellar tendinopathy in elite youth basketballers.

Patellar tendinopathy (PT) is a leading cause of morbidity in jump-landing athletes. Landing mechanics are identified as a factor associated with PT and/or patellar tendon abnormality. This study aimed to identify key jump-landing variables associated with PT. Thirty-six junior elite basketball players (men n = 18, women n = 18) were recruited from a Basketball Australia development camp. Three-dimensional (3D) kinematic and ground reaction force (GRF) data during a stop-jump task were collected as well as ultrasound scans of the patellar tendons and recall history of training load data. Mixed-model factorial analyses of variance were used to determine any significant between-group differences. Of the 23 participants included for statistical analyses, 11 had normal bilateral patellar tendons (controls) and eight reported PT (currently symptomatic); however, the four participants categorized as asymptomatic with patellar tendon abnormality on diagnostic imaging were excluded from statistical analyses due to their small sample size. Athletes with PT displayed a similar knee flexion angle at initial foot-ground contact (IC) and hip extension strategy during a stop-jump horizontal landing. Despite a similar kinematic technique, athletes with PT utilized a strategy of a longer stance duration phase from IC to peak force. This strategy did not lead to those athletes with PT decreasing their peak vertical GRF nor patellar tendon force during landing but enabled these athletes to land with a lower rate of loading (control 59.2 ± 39.3 vs. PT 29.4 ± 33.7 BW.s-1). Athletes with PT still reported significantly reduced training volume (control 4.9 ± 1.8 vs PT 1.8 ± 1.1 sessions/wk; total training time/wk control 2.4 ± 1.0 vs PT 1.4 ± 1.1 h/wk).

Immediate and Short-Term Effects of Short- and Long-Duration Isometric Contractions in Patellar Tendinopathy.

OBJECTIVES: Isometric muscle contractions are used in the management of patellar tendinopathy to manage pain and improve function. Little is known about whether long- or short-duration contractions are optimal to improve pain. This study examined the immediate and short-term (4 weeks) effects of long- and short-duration isometric contraction on patellar tendon pain, and tendon adaptation. DESIGN: Repeated measures within groups. SETTING: Clinical primary care. PATIENTS: Participants (n = 16, males) with patellar tendinopathy. INTERVENTION: Short-duration (24 sets of 10 seconds) or long-duration (6 sets of 40 seconds) isometric knee extension loading (85% maximal voluntary contraction), for 4 weeks. MAIN OUTCOME MEASURE: Immediate change in pain with single-leg decline squat (SLDS) and hop, as well as change in pain and tendon adaptation [within-session anterior-posterior (AP) strain] were assessed over 4 weeks. RESULTS: Pain was significantly reduced after isometric loading on both SLDS (P < 0.01) and hop tests (P < 0.01). Pain and quadriceps function improved over the 4 weeks (P < 0.05). There was significant AP strain at each measurement occasion (P < 0.01). Although transverse strain increased across the training period from ∼14% to 22%, this was not significant (P = 0.08). CONCLUSIONS: This is the first study to show that short-duration isometric contractions are as effective as longer duration contractions for relieving patellar tendon pain when total time under tension is equalized. This finding provides clinicians with greater options in prescription of isometric loading and may be particularly useful among patients who do not tolerate longer duration contractions. The trend for tendon adaptation over the short 4-week study period warrants further investigation.

Is There Any Association Between Foot Posture and Lower Limb-Related Injuries in Professional Male Basketball Players? A Cross-Sectional Study.

BACKGROUND: Several studies have shown that foot posture is related to the incidence of ankle sprains in athletes and in nonathletic populations, but this association has not previously been considered in basketball players. This study investigates the relationship between foot posture and lower limb injuries in elite basketball players. DESIGN AND METHOD: Two hundred twenty participants were recruited as a convenience sample. The players had a mean age of 22.51 ± 3.88 years and a body mass index of 23.98 ± 1.80. The players' medical records were accessed from the preceding 10 years, and injuries were recorded according to their location (knee, foot, and/or ankle). In addition, the Foot Posture Index (FPI) was scored for each player, and their playing positions were noted. RESULTS: An average FPI score of 2.66 was obtained across all players, with guards presenting a significantly lower average FPI of -0.48 (P < 0.001) compared with the rest of playing positions, indicating a more supinated foot. However, center players presented an average FPI of 5.15 (P < 0.001), indicating a more pronated foot. The most common injuries observed were lateral ankle sprain (n = 214) and patellar tendinopathy (n = 126). Patellar tendinopathy was more common in supinated feet (30.08%) compared with 20.7% and 19.8% in pronated and neutral feet, respectively. CONCLUSIONS: The most common lower limb injuries observed in basketball players were lateral ankle sprain and patellar tendinopathy. Patellar tendinopathy was more commonly associated with the supinated feet. Guard players tended to have a more supinated foot, whereas centers presented a more pronated foot.

The Passive Mechanical Properties of Muscles and Tendons in Children Affected by Osgood-Schlatter Disease.

BACKGROUND: Osgood-Schlatter disease (OSD) is a sports-related disorder involving apophysitis, which affects the tibial tuberosity. The identification of factors related to OSD is important for its prevention and early recovery from the disease. This study aimed to compare the passive mechanical properties of the muscle-tendon unit in children affected by an OSD and healthy children, by using ultrasound real-time tissue elastography. METHODS: Eighteen legs affected by OSD (OSD group) and 42 healthy legs (control: CON group) were assessed. The elasticity was obtained from the quadriceps muscles and patella tendon (PT) using real-time tissue elastography. The strain ratio (SR; muscle or tendon/reference ratio: strain rate of the muscle or tendon divided by that of the reference material) was calculated as an indicator of the elasticity of the tissue of interest. RESULTS: The SR of the PT in the OSD group was significantly lower than that in the CON group (P<0.05). We found no significant difference between the groups in terms of the SR value of all muscles (P>0.05). CONCLUSIONS: The results suggest that a PT with a lower SR may be associated with an OSD and that the passive mechanical properties of the quadriceps muscles have limited association with an OSD. LEVELS OF EVIDENCE: Level IV.

Histopathological changes in patellar tendon enthesis of rabbit induced by electrical stimulation intensity.

BACKGROUND: Enthesis injury is a common problem in athletes and workers, which is considered closely related to overuse. However, the early pathophysiologic changes of osteotendinous junction are not well understood, and moreover, few studies investigated the relationship between intensity and pathological changes. The purpose of this study was to evaluate microstructural changes induced by different loading intensities and to find out the threshold intensity. METHODS: Forty-eight New Zealand White rabbits were randomly divided into six groups. One control group, the others were electrically stimulated to contract repetitively for 2 h per day, three days a week. 30% of peak tetanic force (7.06 N) was adopted to stimulate the rabbits in the 100% cyclic loading group. Other groups were stimulated with 20%, 40%, 60% and 80% of this force. After four weeks, prepared samples were stained with hematoxylin and eosin. RESULTS: After 4 weeks of cyclic loading, the shape and the distribution of tendon cells in patellar enthesis changed, the arrangement of collagen fibers became disordered and the tidemark had become irregular or even disappeared. Different stimulus intensity caused a significant change of cell density in different groups (F = 10.19, P < 0.001). The cell densities of tendon were 34.3 ± 7.9 cells/100 µm2 (L60), 38.2 ± 5.9 cells/100 µm2 (L80), 43.8 ± 10.3 cells/100 µm2 (L100) respectively, which had significant difference with CON group 22.5 ± 3.5 cells/100 µm2. The thickness of fibrocartilage zone had no significant difference among the groups. CONCLUSIONS: The changes of histomorphology with the increasing exercise intensity elucidated that the degree of enthesis microdamage was directly related to the intensity of exercises. The findings demonstrated that 18% (used in L60 group) of peak tetanic force was the threshold intensity which could induce pathological changes in enthesis in four weeks.

One Session of Extracorporeal Shockwave Therapy-Induced Modulation on Tendon Shear Modulus is Associated with Reduction in Pain.

The aim of the study was to examine the immediate effect of 1 session of extracorporeal shockwave therapy (ESWT) on patellar tendon stiffness and to explore the relationship between the change in tendon stiffness and the pain intensity. Thirty-four male athletes aged 22.2 ± 3.8 with patellar tendinopathy were recruited. The participants were randomized into ESWT and sham groups. The ESWT group received 1500 impulses of ESWT at 4 Hz with maximal tolerable pain intensity and the sham group received intensities below 0.08 mJ/mm2. Supersonic Shearwave Imaging (SSI) was used to measure tendon shear modulus (an index of tissue stiffness), and a visual analogue scale was used to quantify the pain intensity during compression with 10 lb (4.535 kg) pressure directed on the most tender part and then during a single-leg declined-squat test. A significant reduction in tendon shear modulus (from 57.4 ± 25.5 kPa to 40.6 ± 17.6kPa, p = 0.001) was detected in the ESWT receiving ESWT with an intensity from 0.13-0.33 mJ/mm2 but not the sham group (from 47.7 ± 17.1 kPa to 41.0 ± 12.7 kPa; p = 0.06). In the ESWT group, the change in tendon shear modulus was associated with the change in the intensity of pain during single-legged declined-squat test (ρ = 0.55; p = 0.023) but not pressure pain (p > 0.05). These findings suggest that one session of ESWT induces reduction of tendon stiffness in volleyball and basketball players with patellar tendinopathy. The reduction in tendon stiffness is associated with reduction in pain during single-legged declined-squat test.

Medial and Lateral Patellofemoral Joint Retinaculum Thickness in People With Patellofemoral Pain: A Case-Control Study.

OBJECTIVES: To measure the medial and lateral retinaculum thickness in individuals with and without patellofemoral pain using ultrasound and to assess associations with the symptom duration and function. METHODS: Medial and lateral patellofemoral joint retinaculum thicknesses of 32 knees (16 with patellofemoral pain and 16 asymptomatic) were measured with B-mode ultrasound at 0.5, 1, and 1.5 cm from the patella border. Participants with patellofemoral pain completed a Kujala questionnaire, and both groups underwent a single-leg squat performance assessment. Two-way analyses of variance (site × group) determined the overall effect, and Cohen d values were calculated to describe the magnitude of the difference for each measurement. RESULTS: The groups were matched for age, height, and weight. Compared to controls, participants with patellofemoral pain had thicker lateral (overall effect, P = .03) and medial (overall effect, P < 0.01) retinacula. No correlations between retinaculum thickness and Kujala scores (lateral retinaculum, r = 0.106 [0.5 cm], -0.093 [1 cm], and -0.207 [1.5 cm]; and medial retinaculum, r = 0.059, 0.109, and -0.219), symptom duration (lateral retinaculum, r = 0.001, -0.041, and 0.302; and medial retinaculum, r = -0.027, -0.358, and -0.346), or single-leg squat performance scores (lateral retinaculum, r = 0.051, 0.114, and 0.046; and medial retinaculum, r = -0.119, -0.292, and 0.011) were observed. CONCLUSIONS: Increased lateral and medial retinaculum thickness in individuals with patellofemoral pain compared to controls identifies structural changes that may be associated with the pathogenesis of patellofemoral pain. The absence of a significant correlation between retinaculum thickness and the symptom duration or function further shows a lack of an association between structure and function in individuals with patellofemoral pain.

Does Patellar Tendon Repair With Gastrocnemius Flap Augmentation Effectively Restore Active Extension After Proximal Tibial Sarcoma Resection?

BACKGROUND: A rotational gastrocnemius flap is often used for soft tissue reconstruction after proximal tibia sarcoma resection. However, little is known about the frequency and severity of complications and the recovery of extensor function after this procedure. QUESTIONS/PURPOSES: After gastrocnemius flap reconstruction with split-thickness skin grafting (STSG) to augment the extensor mechanism repair after proximal tibial resection for sarcoma, we asked: (1) What ROM was achieved (including extensor lag and active flexion)? (2) How often did complications and reoperations occur and what caused them? METHODS: Between 1991 and 2014, one surgeon treated 26 patients with proximal tibial resections for primary bone sarcoma. Of these, 18 were reconstructed with the preferred approach: resecting the proximal tibia leaving the patellar tendon in continuity with the tibialis anterior fascia whenever possible (10), cementing a stemmed proximal tibial endoprosthesis, suturing the patellar tendon to the implant, rotating a medial (16) or lateral (two) gastrocnemius flap over the tendon and prosthesis to augment the repair, and covering the flap with STSG. Alternative methods were used when this was technically impossible (one patient), when there was no advantage to secondary soft tissue coverage (two patients), or when the limb could not be salvaged (five patients). Of the 18 treated with gastrocnemius flaps, two were lost to followup or died of disease before the 24-month minimum and excluded; the median followup of the remaining 16 was 6 years (mean, 9.9 years; range, 2.3-21.7 years); three patients died of disease, and four have not been seen within the last 5 years. We reviewed medical records for passive and active extension, maximum flexion achieved, and complications requiring reoperation. ROM in patients with successful limb salvage was graded as excellent (flexion ≥ 110° and no lag), good (flexion 90°-110° and lag ≤ 10°), fair (one function limited: either flexion < 90° or lag > 10°), or poor (both functions limited: flexion < 90° and lag > 10°). RESULTS: At latest followup, three patients had undergone amputation for deep infection. Of those remaining, median active flexion was 110° (mean, 104°; range, 60°-120°) and extensor lag was 0° (mean, 4°; range, 0°-10°). ROM was excellent in nine patients, good in three, fair in one, and poor in none. We observed 18 complications requiring reoperation in 12 patients, including deep infection (four), patellar tendon avulsion/attenuation (three), and flap necrosis (one). Survivorship free from revision or loss of the gastrocnemius flap was 74% (95% confidence interval [CI], 5.6-95.8) at 2, 5, and 10 years. Survivorship free from reoperation for any cause was 74% (95% CI, 52.0-96.0) at 2 years, 52% (95% CI, 25.8-77.8) at 5 years, and 35% (95% CI, 0-61.5) at 10 years using Kaplan-Meier analysis. CONCLUSIONS: Although most patients regained functional ROM including active extension, 12 required reoperation for complications including infection and early extensor mechanism failures. Despite the observed risks, we believe the gastrocnemius flap with STSG should be considered a suitable approach to provide active extension and soft tissue coverage given the paucity of good surgical options for extensor mechanism reconstruction in this challenging clinical setting. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Quantitative magnetic resonance imaging in patellar tendon-lateral femoral condyle friction syndrome: relationship with subtle patellofemoral instability.

OBJECTIVE: To investigate the correlation of patellar tendon-lateral femoral condyle friction syndrome (PTLFCFS) with subtle patellofemoral instability to explore its pathogenesis. MATERIALS AND METHODS: One hundred knees of 80 patients with PTLFCFS were analyzed retrospectively by retrieving magnetic resonance imaging (MRI) data over a 3-year period from our database. Seven quantitative parameters for evaluating patellofemoral stability were measured on MR images, including the Insall-Salvati ratio, tibial tuberosity-trochlear groove (TT-TG) distance, trochlear groove depth, medial trochlear/lateral trochlear length (MT/LT) ratio, medial trochlear/lateral trochlear height (MH/LH) ratio, lateral patellofemoral angle (LPA), and lateral trochlear inclination (LTI) angle. These patellofemoral parameters of the PTLFCFS group and the normal control group were compared (n = 88), and receiving-operator characteristic (ROC) curve analysis was conducted to determine the specificity and sensitivity of these parameters. RESULTS: The trochlear depth, MT/LT, LPA, and LTI angle were significantly lower (p < 0.001) and the Insall-Salvati ratio was significantly higher (p < 0.001) in the PTLFCFS group. However, the TT-TG distance and MH/LH ratio showed no significant difference (p = 0.231 and 0.073 respectively). The area under the ROC curve of the Insall-Salvati ratio, trochlear depth, MT/LT, LPA, and LTI angle were 0.925, 0.784, 0.8, 0.731, and 0.675 respectively. The efficiency of the Insall-Salvati ratio was the highest among those five parameters. CONCLUSION: This study verified the presence of subtle patellofemoral instability by measuring various patellofemoral parameters in patients with PTLFCFS. It confirmed that PTLFCFS is associated with subtle patellofemoral instability and could largely explain the pathogenesis of PTLFCFS.

Isometric Exercise to Reduce Pain in Patellar Tendinopathy In-Season: Is It Effective "on the Road"?

OBJECTIVE: To investigate the effectiveness of an isometric squat exercise using a portable belt, on patellar tendon pain and function, in athletes during their competitive season. DESIGN: Case series with no requirements to change any aspect of games or training. The object of this pragmatic study was to investigate this intervention in addition to "usual management." A control or sham intervention was considered unacceptable to teams. SETTING: In-season. PARTICIPANTS: A total of 25 male and female elite and subelite athletes from 5 sports. INTERVENTION: 5 × 30-second isometric quadriceps squat exercise using a rigid belt completed over a 4-week period. MAIN OUTCOME MEASURES: (1) single-leg decline squat (SLDS)-a pain provocation test for the patellar tendon (numerical rating score of pain between 0 and 10), (2) VISA-P questionnaire assessing patellar tendon pain and function, and (3) self-reported adherence with completing the exercise over a 4-week period. RESULTS: Baseline SLDS pain was high for these in-season athletes, median 7.5/10 (range 3.5-9) and was significantly reduced over the 4-week intervention (P < 0.001, ES r = 0.580, median change 3.5). VISA-P scores improved after intervention (P < 0.001, ES r = 0.568, mean change 12.2 ± 8.9, percentage mean change 18.8%, where minimum clinical important difference of relative change for VISA-P is 15.4%-27%). Adherence was high; athletes reported completing the exercise 5 times per week. CONCLUSIONS: This pragmatic study suggests that a portable isometric squat reduced pain in-season for athletes with patellar tendinopathy (PT). This form of treatment may be effective, but clinical trials with a control group are needed to confirm the results.

Comparison of the Effect of 5 Different Treatment Options for Managing Patellar Tendinopathy: A Secondary Analysis.

OBJECTIVE: Currently, no treatments exist for patellar tendinopathy (PT) that guarantee quick and full recovery. Our objective was to assess which treatment option provides the best chance of clinical improvement and to assess the influence of patient and injury characteristics on the clinical effect of these treatments. DESIGN: A secondary analysis was performed on the combined databases of 3 previously performed double-blind randomized controlled trials. PATIENTS: In total, 138 patients with PT were included in the analysis. INTERVENTIONS: Participants were divided into 5 groups, based on the treatment they received: Extracorporeal shockwave therapy (ESWT) (n = 31), ESWT plus eccentric training (n = 43), eccentric training (n = 17), topical glyceryl trinitrate patch plus eccentric training (n = 16), and placebo treatment (n = 31). MAIN OUTCOME MEASURES: Clinical improvement (increase of ≥13 points on the Victorian Institute of Sport Assessment-Patella score) after 3 months of treatment. RESULTS: Fifty-two patients (37.7%) improved clinically after 3 months of treatment. Odds ratios (ORs) for clinical improvement were significantly higher in the eccentric training group (OR 6.68, P = 0.009) and the ESWT plus eccentric training group (OR 5.42, P = 0.015) compared with the other groups. We found evidence that a high training volume, a longer duration of symptoms, and older age negatively influence a treatment's clinical outcome (trend toward significance). CONCLUSIONS: Our study confirmed the importance of exercise, and eccentric training in particular, in the management of PT. The role of ESWT remains uncertain. Further research focusing on the identified prognostic factors is needed to be able to design patient-specific treatment protocols for the management of PT.

The presence of patellar tendinopathy in the bone-patellar tendon-bone autograft may increase the risk of anterior cruciate ligament graft failure.

PURPOSE: The purpose of this study was to evaluate the influence of patellar tendinopathy on primary anterior cruciate ligament (ACL) reconstruction graft failure when using bone-patellar tendon-bone (BPTB) autograft. METHODS: All patients undergoing primary ACL reconstruction using ipsilateral BPTB with preoperative magnetic resonance imaging (MRI) available for review were approached for eligibility. The medical charts of included patients were reviewed to obtain demographic information, anatomical characteristics, injury characteristics, treatment characteristics, length of follow-up, and presence of graft failure. A single, fellowship-trained, knee-specialist and blinded researcher performed preoperative MRI interpretation of patellar tendinopathy. The presence/absence of patellar tendinopathy (none, mild, moderate, or severe changes) was compared between patients with (cases) and without (controls) failure of ACL reconstruction. There were 559 cases with a median (range) clinical follow-up was 8 (4-30) months and an average age of 21.5 years (82% males). RESULTS: Of the 559 cases, there were 182 (32.6%) with and 377 (67.4%) without patellar tendinopathy. A total of 32 (5.7%) graft failures occurred. There were a significantly higher failure rate in patients with compared to without patellar tendinopathy (p < 0.001), and in patients with compared to without partial tendon tear (p < 0.001). The odds ratio (95% confidence interval) for graft failure was 5.9 (2.7-13.1), 20.8 (6.8-63.9) and 54.4 (5.5-539.4) in patients with patellar tendinopathy (compared to absence of patellar tendinopathy), moderate or severe patellar tendinopathy (compared to none or mild patellar tendinopathy), or partial tendon tear (compared to absence of tendon tear), respectively. CONCLUSION: The presence of patellar tendinopathy increases the risk of BPTB graft failure when used for ACL reconstruction. The use of BPTB autograft is not recommended if patellar tendinopathy is obvious or there are suspicious of partial tendon tear on MRI. In such cases, the surgeon should consider using a different graft. LEVEL OF EVIDENCE: Retrospective cohort analysis, Level III.

Stress Relaxation and Targeted Nutrition to Treat Patellar Tendinopathy.

Patellar tendinopathy is one of the most common afflictions in jumping sports. This case study outlines the rehabilitation of a professional basketball player diagnosed by magnetic resonance imaging (MRI) with a central core patellar tendinopathy within the proximal enthesis. The player undertook a nutrition and strength-based rehabilitation program combining gelatin ingestion and heavy isometric loading of the patellar tendon designed to produce significant stress relaxation as part of their competition schedule and a whole-body training plan. On follow-up one and a half years into the program an independent orthopedic surgeon declared the tendon normal on MRI. Importantly, the improved MRI results were associated with a decrease in pain and improved performance. This case study provides evidence that a nutritional intervention combined with a rehabilitation program that uses stress relaxation can improve clinical outcomes in elite athletes.

Clinical Measures and Their Contribution to Dysfunction in Individuals With Patellar Tendinopathy.

CONTEXT: Patellar tendinopathy (PT) is prevalent in physically active populations, and it affects their quality of living, performance of activity, and may contribute to the early cessation of their athletic careers. A number of previous studies have identified contributing factors for PT; however, their contributions to self-reported dysfunction remain unclear. OBJECTIVE: The purpose of this investigation was to determine if strength, flexibility, and various lower-extremity static alignments contributed to self-reported function and influence the severity of PT. DESIGN: Cross-sectional research design. SETTING: University laboratory. PARTICIPANTS: A total of 30 participants with PT volunteered for this study (age: 23.4 [3.6] y, height: 1.8 [0.1] m, mass: 80.0 [20.3] kg, body mass index: 25.7 [4.3]). MAIN OUTCOME MEASURES: Participants completed 7 different patient-reported outcomes. Isometric knee extension and flexion strength, hamstring flexibility and alignment measures of rearfoot angle, navicular drop, tibial torsion, q-angle, genu recurvatum, pelvic tilt, and leg length differences were assessed. Pearson's correlation coefficients were assessed to determine significantly correlated outcome variables with each of the patient-reported outcomes. The factors with the highest correlations were used to identify factors that contribute the most to pain and dysfunction using backward selection, linear regression models. RESULTS: Correlation analysis found significant relationships between questionnaires and body mass index (r = -.35-.46), normalized knee extension (r = .38-.50) and flexion strength (r = -.34-.50), flexibility (r = .32-.38, q-angle (r = .38-.56), and pelvic tilt (r = -.40). Regression models (R2 = .22-.54) identified thigh musculature strength and supine q-angle to have greatest predictability for severity in patient-reported outcomes. CONCLUSIONS: These findings put an emphasis of bodyweight management, improving knee extensor and flexor strength, and posterior flexibility in PT patients.

Don't Assume the Control Group Is Normal-People with Asymptomatic Tendon Pathology Have Higher Pressure Pain Thresholds.

Objective: Pain pressure thresholds (PPT) are used to study peripheral and central pain processing. In the tendon, pathological changes may exist without pain. This pilot study aimed to compare PPT between individuals with normal tendons and asymptomatic tendon pathology, and between individuals with and without a history of tendon pain. Methods: The patellar, Achilles, and supraspinatus tendons of 128 asymptomatic participants were examined with ultrasound. Global PPT average was determined using a digital algometer at the patellar tendon, quadriceps muscle, L3 spinous process, and deltoid muscle insertion. Participants were separated into three groups: (1) healthy control group (no pathology, no history of pain), (2) tendon pathology at any site without a history of pain, (3) history of tendon pain anywhere. Results: There were 92 controls, seven with asymptomatic pathology and 29 with a history of tendon pain. Asymptomatic tendon pathology at any site (without a history of pain) was associated with globally increased PPTs compared with controls (P < 0.001, pathology N = 7, N = 92 controls). Matched pair analysis remained significant (P < 0.004). A history of tendon pain was associated with globally increased PPTs compared with the control group (P = 0.026). Matched pair analysis was not significant (P = 0.122). Conclusions: Asymptomatic tendon pathology is associated with higher PPTs. These findings point toward central nervous system adaptations but in a novel way-central desensitization. This challenges the validity of conclusions drawn from PPT studies that do not verify normal structure in the control group; artificial inflation of control group data may incorrectly indicate decreased PPTs in the comparison group.