Musculotendinous Junction Research Articles

Determinants of Return to Play After the Nonoperative Management of Hamstring Injuries in Athletes

Background: It is important for clinicians to rely on suitable prognosis factors after hamstring injuries because of the high incidence of these injuries and time away from athletic activities. Purpose: To summarize the current literature on factors that influence return to play after a hamstring injury in athletes. Study Design: Systematic review. Methods: A computer-assisted literature search of CINAHL, MEDLINE, Embase, and EBM Reviews databases (and a manual search of the reference lists of all selected articles) was conducted using keywords related to hamstring injuries and return to play. The literature review criteria included (1) patients with an acute hamstring or posterior thigh injury; (2) a randomized controlled trial, cohort study, case-control study, case series, or prospective or retrospective design; (3) information on rehabilitation, physical therapy, clinical assessment, imaging techniques, and return to play; and (4) studies written in English or French. Results: The search strategy identified 914 potential articles, of which 24 met the inclusion criteria. In terms of the clinical assessment, the following factors were associated with a longer recovery time: stretching-type injuries, recreational-level sports, structural versus functional injuries, greater range of motion deficit with the hip flexed at 90°, time to first consultation >1 week, increased pain on the visual analog scale, and >1 day to be able to walk pain free after the injury. As for magnetic resonance imaging studies, the following factors correlated with a longer recovery time: positive findings; higher grade of injury; muscle involvement >75%; complete transection; retraction; central tendon disruption of the biceps femoris; proximal tendon involvement; shorter distance to the ischial tuberosity; length of the hamstring injury; and depth, volume, and large cross-sectional area. With respect to ultrasound studies, the following factors were associated with a poor prognosis: large cross-sectional area, injury outside the musculotendinous junction, hematoma, structural injury, and injury involving the biceps femoris. Lastly, rehabilitation approaches that included hamstring loading during extensive lengthening or 4 daily sessions of static hamstring stretching led to shorter rehabilitation times. Conclusion: Numerous determinants have an effect on return to play after a hamstring injury in athletes. It is important for sports professionals to be aware of those determinants to guide athletes through the rehabilitation process and refine return-to-play strategies.

Reconstitution of the complete rupture in musculotendinous junction using skeletal muscle-derived multipotent stem cell sheet-pellets as a “bio-bond”

Background. Significant and/or complete rupture in the musculotendinous junction (MTJ) is a challenging lesion to treat because of the lack of reliable suture methods. Skeletal muscle-derived multipotent stem cell (Sk-MSC) sheet-pellets, which are able to reconstitute peripheral nerve and muscular/vascular tissues with robust connective tissue networks, have been applied as a “bio-bond”.Methods. Sk-MSC sheet-pellets, derived from GFP transgenic-mice after 7 days of expansion culture, were detached with EDTA to maintain cell–cell connections. A completely ruptured MTJ model was prepared in the right tibialis anterior (TA) of the recipient mice, and was covered with sheet-pellets. The left side was preserved as a contralateral control. The control group received the same amount of the cell-free medium. The sheet-pellet transplantation (SP) group was further divided into two groups; as the short term (4–8 weeks) and long term (14–18 weeks) recovery group. At each time point after transplantation, tetanic tension output was measured through the electrical stimulation of the sciatic nerve. The behavior of engrafted GFP+ tissues and cells was analyzed by fluorescence immunohistochemistry.Results. The SP short term recovery group showed average 64% recovery of muscle mass, and 36% recovery of tetanic tension output relative to the contralateral side. Then, the SP long term recovery group showed increased recovery of average muscle mass (77%) and tetanic tension output (49%). However, the control group showed no recovery of continuity between muscle and tendon, and demonstrated increased muscle atrophy, with coalescence to the tibia during 4–8 weeks after operation. Histological evidence also supported the above functional recovery of SP group. Engrafted Sk-MSCs primarily formed the connective tissues and muscle fibers, including nerve-vascular networks, and bridged the ruptured tendon–muscle fiber units, with differentiation into skeletal muscle cells, Schwann cells, vascular smooth muscle, and endothelial cells.Discussion. This bridging capacity between tendon and muscle fibers of the Sk-MSC sheet-pellet, as a “bio-bond,” represents a possible treatment for various MTJ ruptures following surgery.

Anatomy of the long head of biceps femoris: An ultrasound study.

Hamstring strains, particularly involving the long head of biceps femoris (BFlh) at the proximal musculotendinous junction (MTJ), are commonly experienced by athletes. With the use of diagnostic ultrasound increasing, an in-depth knowledge of normal ultrasonographic anatomy is fundamental to better understanding hamstring strain. The aim of this study was to describe the architecture of BFlh, using ultrasonography, in young men and cadaver specimens. BFlh morphology was examined in 19 healthy male participants (mean age 21.6 years) using ultrasound. Muscle, tendon and MTJ lengths were recorded and architectural parameters assessed at four standardised points along the muscle. Measurement accuracy was validated by ultrasound and dissection of BFlh in six male cadaver lower limbs (mean age 76 years). Intra-rater reliability of architectural parameters was examined for repeat scans, image analysis and dissection measurements. Distally the BFlh muscle had significantly (P < 0.05) shorter fascicles and larger pennation angles than proximal sites. Agreement between ultrasound and dissection (cadaver study) was excellent for all architectural parameters, except pennation angle (PA), and MTJ length. All other measures demonstrated good-excellent repeatability. BFlh is not uniform in architecture when imaged using ultrasound. It is likely that its distal-most segment is better suited for force production in comparison to the more proximal segments, which show excursive potential, traits which possibly contribute to the high rate of injury at the proximal MTJ. The data presented in this study provide specific knowledge of the normal ultrasonographic anatomy of BFlh, which should be of assistance in analysing BFlh injury via imaging. Clin. Anat. 29:738-745, 2016. © 2016 Wiley Periodicals, Inc.

Triple-Loaded Single-Row versus Suture-Bridge Double-Row Rotator Cuff Tendon Repair with Platelet Rich Plasma Fibrin Membrane: A Randomized Control Trial

Triple-Loaded Single-Row versus Suture-Bridge Double-Row Rotator Cuff Tendon Repair with Platelet Rich Plasma Fibrin Membrane: A Randomized Control Trial

Regional Difference In Gastrocnemius Tension During Passive Stretching As Assessed With Shear Wave Elastography

Muscle strain injuries occur when the muscle is either stretched passively or activated during stretch. Calf strain injuries are most commonly found in the medial gastrocnemius (MG), especially at the distal musculotendinous junction. One of the reasons for the susceptibility of musculotendinous junction for strain injuries may be that the distal region of MG is stretched more than the medial belly region. Muscle tension during passive stretching can be estimated from shear elastic modulus measured by shear wave elastography. PURPOSE: To investigate the regional difference in MG tension during passive stretching, shear elastic modulus at the distal and medial belly regions of the MG was assessed by shear-wave elastography. METHODS: Twenty-two healthy men and 25 healthy women participated in this study. Shear elastic moduli at the distal and medial belly regions of the MG were measured with the ankle joint positions at 30° plantarflexion (PF), a neutral anatomical position (NE), and 20° dorsiflexion (DF). The regional differences in the shear elastic modulus were tested with a two-way analysis of variance (region of the MG × ankle joint position), followed by t-tests with Bonferroni correction, with the significance set at P < 0.05. RESULTS: Shear elastic modulus was not significantly different between the distal and medial belly regions at PF (distal region: 5.7 ± 2.0 kPa; medial belly region: 5.0 ± 1.4 kPa) and NE (distal region: 9.8 ± 1.6 kPa; medial belly region: 9.9 ± 1.8 kPa), but it was significantly higher at the distal region (40.7 ± 10.1 kPa) compared with the medial belly region (35.9 ± 9.1 kPa) at DF. CONCLUSIONS: Regional difference in MG tension during passive stretching was observed in the ankle joint position where the MG is sufficiently lengthened, which could lead to muscle strain injuries at the distal musculotendinous junction of the MG. The study was supported by JSPS KAKENHI (Grant Number 15K16500).

Imaging of rectus femoris proximal tendinopathies.

The rectus femoris is the most commonly injured muscle of the anterior thigh among athletes, especially soccer players. Although the injury pattern of the muscle belly is well documented, less is known about the anatomy and specific lesions of the proximal tendons. For each head, three distinctive patterns may be encountered according to the location of the injury, which can be at the enthesis, within the tendon, or at the musculotendinous junction. In children, injuries correspond most commonly to avulsion of the anteroinferior iliac spine from the direct head and can lead to subspine impingement. Calcific tendinitis and traumatic tears may be encountered in adults. Recent studies have shown that traumatic injuries of the indirect head may be underdiagnosed and that injuries of both heads may have a surgical issue. Finally, in the case of tears, functional outcome and treatment may vary if the rupture involves one or both tendons and if the tear is partial or complete. Thus, it is mandatory for the radiologist to know the different ultrasound and magnetic resonance imaging (MRI) patterns of these lesions in order to provide accurate diagnosis and treatment. The purpose of this article is to recall the anatomy of the two heads of rectus femoris, describe a reliable method of assessment with ultrasound and MRI and know the main injury patterns, through our own experience and literature review.

Qualitative Assessment and Quantitative Analysis of the Long Head of the Biceps Tendon in Relation to the Pectoralis Major Tendon Humeral Insertion: An Anatomic Study

To qualitatively assess and to quantitatively analyze the long head of the biceps tendon (LHBT) in the region of the pectoralis major (PM). From 11 fresh cadaveric donors, 20 cadaveric shoulders without operative scars were dissected-mean age, 76.9years (range, 61 to 93years); male, 75%; left-sided, 55%; mean height, 67.8 inches (range, 61 to 71 inches); mean weight, 148.1 pounds (range, 106 to 176 pounds). Two specimens with discovered ruptures were excluded. The LHBT circumference was measured at the anterior edge of supraspinatus, suprapectorally, midpectorally, and subpectorally. The muscle was then removed from the LHBT and the circumference was again measured at the supra-, mid-, and subpectoral levels. These data were used to calculate the area of the tendon. All measurements were performed by 2 independent observers. Statistical analysis was performed to assess reliability of data and the difference between serial measurements. The mean calculated percentage tendon decreased from 86.7% at the superior edge of the PM to 49.8% at the midpoint of the PM and to 17.5% at the inferior edge of the PM. Distal to the PM, the LHBT was composed of a small percentage of tendon to muscle, which may have implications for the mechanical strength of fixation of tenodesis. The anatomic location of the musculotendinous junction of the LHBT began proximal to the superior edge of the PM tendon, which implies that restoration of anatomic tensioning may require a more proximal docking site than previously described. Tenodesis performed between the midpoint of the PM insertion and more distal points involves a significant portion of muscle, which may not be optimal. Tenodesis performed between the midpoint of the PM insertion and more distal points involves a significant portion of muscle, which may affect the mechanical strength or optimal choice of fixation location.

Tendon retraction with rotator cuff tear causes a decrease in cross-sectional area of the supraspinatus muscle on magnetic resonance imaging

Muscle atrophy and fatty degeneration of the rotator cuff muscles have been reported as negative prognostic indicators after rotator cuff repair. Although the Y-shaped view is widely used for measuring the cross-sectional area of the supraspinatus muscle, the contribution of retraction of the torn tendon as well as muscle atrophy must be considered. The purpose of this study was to clarify the relationship between cross-sectional area and tendon retraction or size of the tear. This study included 76 shoulders that were evaluated arthroscopically for the presence and size of tears. Cross-sectional areas of rotator cuff muscles were measured from the Y-shaped view to 3 more medial slices. The occupation ratio and tangent sign were evaluated on the Y-shaped view. The retraction of torn tendon was also measured on the oblique coronal images. On the Y-shaped view, the cross-sectional area of the supraspinatus and the occupation ratio decreased in conjunction with the increase in tear size. A significant decrease in cross-sectional area was noted only in large and massive tears on more medial slices from the Y-shaped view. Significant decreases in the cross-sectional area of the infraspinatus were observed in large and massive tears on all images. A negative correlation was found between tendon retraction and cross-sectional area, which was strongest on the Y-shaped view. To avoid the influence of retraction of the supraspinatus tendon, sufficient medial slices from the musculotendinous junction should be used for evaluation of muscle atrophy.

Closed Traumatic Avulsion of Extensor Digitorium Communis and Extensor Indicis Proprius of Index Finger at the Musculotendinous Junction

Closed Traumatic Avulsion of Extensor Digitorium Communis and Extensor Indicis Proprius of Index Finger at the Musculotendinous Junction

Effects of long-term self-massage at the musculotendinous junction on hamstring extensibility, stiffness, stretch tolerance, and structural indices: A randomized controlled trial

ObjectivesThe purpose of this study was to examine the effect of long-term self-massage at the musculotendinous junction on hamstring extensibility, stiffness, stretch tolerance, and structural indices. DesignSingle-blind, randomized, controlled trial. SettingLaboratory. ParticipantsThirty-seven healthy men. InterventionThe right or left leg of each participant was randomly assigned to the massage group, and the other leg was assigned to the control group. The participants conducted self-massage at the musculotendinous junction for 3 min daily, five times per week, for 12 weeks. Main outcome measuresHamstring extensibility, stiffness, stretch tolerance, and structural indices were measured by a blinded examiner prior to the massage intervention and after 6 and 12 weeks of intervention. ResultsThe maximum hip flexion angle (HFA) and the maximum passive pressure after 6 and 12 weeks of intervention in the massage group were significantly higher than prior to intervention. The visual analog scale (for pain perception) at maximum HFA, the stiffness of the hamstring, and the structural indices did not differ in either group over the 12 week period. ConclusionsOur results suggest that long-term self-massage at the musculotendinous junction increases hamstring extensibility by improving stretch tolerance. However, this intervention does not change hamstring stiffness. Clinical trial registration numberUniversity Hospital Medical Information Network registration number UMIN000011233.

Triple-Loaded Single-Row Versus Suture-Bridge Double-Row Rotator Cuff Tendon Repair With Platelet-Rich Plasma Fibrin Membrane: A Randomized Controlled Trial

To compare the structural healing and clinical outcomes of triple-loaded single-row with suture-bridging double-row repairs of full-thickness rotator cuff tendons when both repair constructs are augmented with platelet-rich plasma fibrin membrane. A prospective, randomized, consecutive series of patients diagnosed with full-thickness rotator cuff tears no greater than 3cm in anteroposterior length were treated with a triple-loaded single-row (20) or suture-bridging double-row (20) repair augmented with platelet-rich plasma fibrin membrane. Theprimary outcome measure was cuff integrity by magnetic resonance imaging (MRI) at 12months postoperatively. Secondary clinical outcome measures were American Shoulder and Elbow Surgeons, Rowe, Simple Shoulder Test, Constant, and Single Assessment Numeric Evaluation scores. The mean MRI interval was 12.6months (range, 12-17months). A total of 3 of 20 single-row repairs and 3 of 20 double-row repairs (15%) had tears at follow-up MRI. The single-row group had re-tears in 1 single tendon repair and 2 double tendon repairs. All 3 tears failed at the original attachment site (Cho type 1). In the double-row group, re-tears were found in 3 double tendon repairs. All 3 tears failed medial to the medial row near the musculotendinous junction (Cho type 2). All clinical outcome measures were significantly improved from the preoperative level (P < .0001), but there was no statistical difference between groups postoperatively. There is no MRI difference in rotator cuff tendon re-tear rate at 12months postsurgery between a triple-loaded single-row repair or a suture-bridging double-row repair when both are augmented with platelet-rich plasma fibrin membrane. No difference could be demonstrated between these repairs on clinical outcome scores. I, Prospective randomized study.

Porcine urinary bladder matrix does not generate appreciable de novo muscle tissue in rat models of volumetric muscle loss injury

Event Abstract Back to Event Porcine urinary bladder matrix does not generate appreciable de novo muscle tissue in rat models of volumetric muscle loss injury Amit Aurora1, Janet L. Roe1, Benjamin T. Corona1 and Thomas J. Walters1 1 US Army Institute of Surgical Research, Extremity Trauma Research and Regenerative Medicine, United States Background: The high prevalence of volumetric muscle loss (VML) among battlefield injuries has stimulated research efforts aimed at regenerating muscle de novo using tissue engineering approaches. Extracellular matrix (ECM) scaffolds, in particular, have been extensively used based on their ability to provide a bio-inductive platform that supports endogenous cell recruitment, proliferation, and differentiation, ultimately improving healing of the tissue[1][2]. Recently, surgeons have used commercially available porcine derived urinary bladder matrix (UBM) to repair lower extremity VML in a small cohort of patients[3][4]. The porcine UBM scaffold has clinically been used for surgical reinforcement of soft tissue where weakness exits and general wound management-indications for which it has been approved by the U.S. Food and Drug Administration. However, there is need to establish evidence that will support further clinical use of the scaffold for the repair of traumatic muscle injuries. The overarching objective of this study is to investigate the efficacy of the porcine UBM scaffold as a tissue engineered strategy for the repair of traumatic muscle injuries. Methods: A musculotendinous junction (MTJ) or volumetric muscle loss (VML) injury was created in Lewis rats. For the MTJ injury, the defect created either received no repair or was repaired with a 6-layer MatriStem Surgical Matrix PSMX (time points: 2, 4, or 8 weeks). For the VML injury, the defect created received no repair, repaired with autograft tissue or with a 3-layer MatriStem Surgical Matrix PSM (time points: 2, 8, or 16 weeks). The m-ECM was only investigated at 2 weeks. Upon finding that the porcine UBM scaffold partially restored the muscle function in VML injury at eight weeks; a second study was performed to determine if physical rehabilitation during an eight week period would further improve function. The porcine UBM repaired rats were given free access to running wheels beginning at one week or four weeks post - injury. In vivo function testing was done (MTJ injury: 4 weeks post-injury; VML injury: 8 and 16 weeks post-injury) followed by tissue harvest for histological analysis. Results and Discussion: The porcine UBM scaffold did not promote appreciable muscle tissue regeneration as demonstrated in two distinct models of extremity VML. The porcine UBM scaffold completely resorbed when used as an interpositional graft for MTJ repair. When used to augment a VML defect surrounded by muscle and fascia, the porcine UBM scaffold improves the contractile properties of the injured limb by 17%, but does so without significant muscle fiber regeneration compared to autograft that showed robust regeneration (A-C). Finally, inclusion of physical rehabilitation (i.e., voluntary wheel running) did not improve tissue remodeling or functional improvements observed with scaffold implantation alone. Conclusions: The scaffold may not be suitable for clinical repair of MTJ injuries. The porcine UBM scaffold when used for VML repair may hasten functional recovery not due to significant muscle regeneration, but through force transmission via scaffold mediated fibrosis. The study suggests that if appreciable muscle generation is to be realized, combinatorial approaches that incorporate myogenic cells, a myoconductive scaffold, and a vasculogenic accelerant need to be developed.

Two cases of chronic knee pain caused by unusual injuries to the popliteus tendon.

Injuries to the popliteus tendon are less frequent than injuries to the menisci or ligamentous structures of the knee. When they do occur, injuries to the popliteus tendon tend to be the result of trauma and associated with injuries to other components of the knee. The most commonly seen injuries include tears at the musculotendinous junction and avulsion tears at the lateral femoral condyle insertion site. This report presents two unusual injuries of the popliteus tendon in patients with chronic knee pain: an isolated split tear of the tendon and a subluxed tendon residing within the lateral joint space.

Optimal Needle Placement for Extensor Hallucis Longus Muscle: A Cadaveric Study.

ObjectiveTo determine the midpoint (MD) of extensor hallucis longus muscle (EHL) and compare the accuracy of different needle electromyography (EMG) insertion techniques through cadaver dissection.MethodsThirty-eight limbs of 19 cadavers were dissected. The MD of EHL was marked at the middle of the musculotendinous junction and proximal origin of EHL. Three different needle insertion points of EHL were marked following three different textbooks: M1, 3 fingerbreadths above bimalleolar line (BML); M2, junction between the middle and lower third of tibia; M3, 15 cm proximal to the lower border of both malleoli. The distance from BML to MD (BML_MD), and the difference between 3 different points (M1–3) and MD were measured (designated D1, D2, and D3, respectively). The lower leg length (LL) was measured from BML to top of medial condyle of tibia.ResultsThe median value of LL was 34.5 cm and BML_MD was 12.0 cm. The percentage of BML_MD to LL was 35.1%. D1, D2, and D3 were 7.0, 0.9, and 3.0 cm, respectively. D2 was the shortest, meaning needle placement following technique by Lee and DeLisa was closest to the actual midpoint of EHL.ConclusionThe MD of EHL is approximately 12 cm above BML, and about distal 35% of lower leg length. Technique that recommends placing the needle at distal two-thirds of the lower leg (M2) is the most accurate method since the point was closest to muscle belly of EHL.

Acute Traumatic Musculotendinous Avulsion of the Flexor Pollicis Longus Tendon Treated with Primary Flexor Digitorum Superficialis Transfer: A Novel Technique of Management.

Traumatic musculotendinous junction avulsions are rare injuries except in avulsion amputations. They pose a significant challenge to the treating surgeon. We present a 24-year-old male who sustained an open musculotendinous avulsion of the flexor pollicis longus tendon. He was treated with primary tendon transfer using the flexor digitorum superficialis of ring finger, in flexor zone 3. The functional result at 10 months following surgery was excellent.

Proximal hamstring morphology and morphometry in men: an anatomic and MRI investigation.

The proximal musculo-tendinous junction (MTJ) is a common site of hamstring strain injury but the anatomy of this region is not well defined. A morphometric analysis of the proximal MTJs of biceps femoris long head (BFlh), semitendinosus (ST), and semimembranosus (SM) was undertaken from dissection of 10 thighs from five male cadavers and magnetic resonance imaging of 20 thighs of10 active young men. The length, volume, and cross-sectional area of the proximal tendon, MTJ and muscle belly, and muscle-tendon interface area were calculated. Inboth groups, MTJs were reconstructed three-dimensionally. The proximal tendons and MTJs were expansive, particularly within SM and BFlh. Morphology varied between muscles although length measurements within individual muscles were similar in cadavers and young men. Semimembranosus had the longest proximal tendon (cadavers: mean 33.6±2.0cm; young men: mean 31.7±1.6cm) and MTJ (>20cm in both groups) and the greatest muscle-tendon interface area, followed by BFlh and ST. Mean muscle belly volumes were more than three times greater in young men than elderly male cadavers (P<0.001). These unique morphometric data contribute to a better understanding of hamstring anatomy, an important factor in the pathogenesis of hamstring strain injury.

Hip Arthroscopy and Heterotopic Ossification: Is NSAID Prophylaxis Justified? Commentary on an article by James T. Beckmann, MD, MS, et al.: "Effect of Naproxen Prophylaxis on Heterotopic Ossification Following Hip Arthroscopy: A Double-Blind Randomized Placebo-Controlled Trial".

Heterotopic ossification (HO) is a process in which unwanted and potentially disabling bone tissue forms in abnormal locations such as muscles, musculotendinous junctions, and joint capsules. It may occur after trauma and after surgery. It is well known around the elbow and hip following fracture surgery and total hip replacement. The number of hip arthroscopies performed has increased exponentially over the last decade, and HO has become well recognized following this mini-invasive procedure. Although not as commonly experienced as a clinical problem, it is frequently demonstrated on postoperative radiographs. It is therefore of interest to investigate whether this abnormal bone formation can be reduced in a controlled study. Nonsteroidal antiinflammatory drugs (NSAIDs) have been used to prevent HO for years in other settings and are also commonly used following hip arthroscopy. However, NSAIDs may also cause serious complications, and knowledge about the effect and risk in each specific indication is important. The article by Beckmann et al. addressed this problem in a well-conducted double-blind randomized controlled trial (RCT) in which three weeks of treatment with 500 mg of naproxen twice daily was compared with a placebo. They found a remarkable difference between the NSAID group and the placebo group with regard to radiographic findings of HO (documented in 4% and 46% of the patients, respectively). Medication compliance was 69% overall, and minor adverse events were reported in 42% in the treatment group and 35% in the control group. Only one patient developed symptomatic HO that required revision surgery. Unfortunately, few RCTs have been performed in orthopaedics, including the quickly evolving field of hip arthroscopy. New techniques have been developed and implemented without full knowledge of the benefit for the patients and how to select the right treatment for the right patient. In a PubMed search for “hip arthroscopy,” 801 studies were found, but when the search was limited to RCTs there were eight (and all were not actually RCTs). However, there is promising research under way: RCTs on the general efficacy of hip arthroscopy are ongoing. The study by Beckmann et al. is an important and welcomed contribution to this so far limited number of Level-I hip arthroscopy studies. NSAIDsmay affect tissue healing. Healing of soft tissue (such as a tendon) to bone has been shown to be impaired byNSAIDs in experimental studies. A negative effect of NSAIDs on the healing of the sutured labrum or capsule in hip arthroscopy may therefore be an issue. NSAIDs have potential serious side effects, and although Beckmann et al. did not report serious or fatal complications in their study of 108 patients, they may occur sooner or later in a larger patient population. Clinically relevant HO is uncommon, and this has to be weighed against the risk of serious side effects caused by NSAIDs. Another question is whether the HO is a temporary phenomenon. A follow-up study of this patient cohort would be of great interest to see to what extent the HO develops further, is reduced, or disappears. This well-performed double-blind RCT documents that NSAIDs can reduce the frequency of radiographic evidence of HO following hip arthroscopy to a minimum. However, the clinical benefit and potential harm of routine NSAID prophylaxis are still unknown. As the authors point out, the lowest dose and shortest duration of NSAID prophylaxis that still prevent HO remain to be determined. This important study raises new questions, and there are many possible directions for further research in this field. Sverre Loken, MD, PhD* Oslo University Hospital, Oslo, Norway

Surgical Management of Recurrent Musculotendinous Hamstring Injury in Professional Athletes.

Background:Hamstring injury is the most common muscular lesion in athletes. The conservative treatment is well described, and surgical management is often indicated for proximal tendinous avulsions. To our knowledge, no surgical treatment has been proposed for failure of conservative treatment in musculotendinous hamstring lesions.Purpose:To describe the surgical management of proximal and distal hamstring musculotendinous junction lesions in professional athletes after failure of conservative treatment.Study Design:Case series; Level of evidence, 4.Methods:A consecutive series of 10 professional athletes, including 4 soccer players, 4 rugby players, and 2 handball players, underwent surgical intervention between October 2010 and June 2014 for the treatment of recurrent musculotendinous hamstring injuries. All athletes had failed at least 3 months of conservative treatment for a recurrent musculotendinous hamstring injury. Surgical resection of the musculotendinous scar tissue was performed using a longitudinal muscular suture. Lower Extremity Functional Scale (LEFS) and Marx scores were obtained at the 3-month follow-up, and a final phone interview was completed to determine recurrence of hamstring injury and return to previous level of play.Results:The mean age at surgery was 25.2 years (range, 19-35 years). The musculotendinous hamstring lesions involved 8 semitendinosus and 2 biceps femoris, with 6 injuries located proximally and 4 distally. Conservative treatment lasted a mean 5.1 months (range, 3-9 months) after last recurrence, and the patients had an average of 2.7 (range, 2-5) separate incidents of injury recurrence before surgical intervention was decided upon. At the 3-month follow-up, all patients had Marx activity scores of 16 and LEFS scores of 80. All 10 patients returned to the same level of play at a mean 3.4 months (range, 2-5 months). At a mean follow-up of 28.7 months, none of the athletes had suffered a recurrence. No surgical complication was encountered.Conclusion:In cases of failed conservative treatment of musculotendinous hamstring lesions, surgical intervention may be a viable treatment option in professional athletes and allows the patient to return to the same level of play.

Arthroscopic Treatment of Isolated Teres Minor Tendon Tear: A Case Report

Arthroscopic repair of an isolated teres minor tendon tear without associated shoulder joint pathology has not been reported in- the literature. We report on a case of isolated teres minor tendon tear after trauma. The patient complained of severe shoulder pain and pro-gressive limited range of motion 4 months after the injury. Magnetic resonance imaging showed a full-thickness tear of the teres minor tendon at its musculotendinous junction and arthroscopic repair was performed. At 2 years follow-up, satisfactory clinical and radiologi-cal outcomes were observed with return to pre-injury level. Here, the authors report this case and provide a review of literature. (Clin Shoulder Elbow 2015;18(3):159-161)Key Words: Teres minor tear; Musculotendionus junction; Arthroscopic repair

Microvascular blood flow in normal and pathologic rotator cuffs

Microvascular blood flow in the tendon plays an important role in the pathogenesis of rotator cuff abnormalities. There are conflicting views about the presence of a hypovascular zone in the supraspinatus tendon. Besides, no studies have looked at the pattern of blood flow around a partial-thickness tear. Our aim was to measure microvascular blood flow in normal and a range of pathologic rotator cuff tendons using laser doppler flowmetry. A total of 120 patients having arthroscopic shoulder surgery were divided into 4 equal groups on the basis of their intraoperative diagnosis: normal rotator cuff, subacromial impingement syndrome, and partial-thickness or full-thickness rotator cuff tear. Microvascular blood flow was measured at 5 different regions of each cuff using a laser doppler probe. The values were compared to assess variability within and between individuals. Total blood flow was greater in the normal rotator cuff group compared with the groups with pathologic rotator cuffs, with the largest difference seen in the subacromial impingement group. Within individuals, blood flow was highest at the musculotendinous junction and lowest at the lateral insertional part of the tendon. Among groups, the blood flow was significantly lower at the anteromedial and posteromedial cuff in the groups with impingement and full-thickness tears compared with the group with normal cuff. Real-time in vivo laser doppler analysis has shown that microvascular blood flow is not uniform throughout the supraspinatus tendon. Blood flow in the pathologic supraspinatus tendon was significantly lower compared with the normal tendon.