Objectives

Rotator cuff tears are among the most common and debilitating upper extremity injuries. Chronic cuff tears result in atrophy and an infiltration of fat into the muscle, a condition commonly referred to as ‘fatty degeneration’. While stem cell therapies hold promise for the treatment of cuff tears, a suitable immunodeficient animal model that could be used to study human or other xenograft-based therapies for the treatment of rotator cuff injuries had not previously been identified.

Introduction and purpose: The functional result of the functional repair of the rotator cuff is multifactorial. The purpose of this study was to assess the influence of supraspinatus and infraspinatus fatty degeneration prior to surgery on the functional result of open rotator cuff repair surgeries. Materials and methods: The study comprised 32 patients (19 females and 13 males) operated on for a rotator cuff tear by means of open surgery. Mean age: 58.16. The right arm was involved in 20 cases, whereas the left one was involved in the remaining 12. The acromion was type II in 28 cases and type III in 4. In all cases a previous MRi was available. The analysis of fatty degeneration was made on the basis of Goutallier’s criteria. The assessment of the functional result was made according to Constant’s score. Minimum follow-up: 1 year. Results: Mean Constant score: preop 51.41 (range: 30–69); postop (at the end of follow-up) 83 (range: 77–100). Fatty degeneration of the supraspinatus was deg. I in 32.25% of cases and deg. II in 45.16%. As regards the infraespinatus, 38,7% of cases had no fatty degeneration and 41.93% had deg. I. No significant differences were found regarding the post Constant score between patients with deg. 0-I supraspinatus fatty degeneration and patients with 0-I infraspinatus fatty degeneration (p 0.604) or between patients with deg. II-III-IV supraspinatus fatty degeneration and those with deg. 0-I infraspinatus fatty degeneration (p.654). Conclusions: (1) Surgical repairs of rotator cuff tears lead to a satisfactory final functional result. (2) Considering the size of our sample, there do not seem to exist significant differences with respect to functional result between patients with supraspinatus (degrees 0–4) and patients with infraspinatus fatty degeneration (limited to deg. 0–1)

Introduction. Patients with hip osteoarthritis have a substantial loss of muscular strength in the affected limb compared to the healthy limb preoperatively, but there is very little quantitative information available on preoperative muscle atrophy and degeneration and their influence on postoperative quality of life (QOL) and the risk of falls. The purpose of the present study were two folds; to assess muscle atrophy and degeneration of pelvis and thigh of patients with unilateral hip osteoarthritis using computed tomography (CT) and to evaluate their impacts on postoperative QOL and the risk of falls. Methods. We used preoperative CT data of 20 patients who underwent primary total hip arthroplasty. The following 17 muscles were segmented with our developed semi-automated segmentation method: iliacus, gluteus maximus, gluteus medius, gluteus minimus, rectus femoris, tensor facia lata, adductors, pectinus, piriformis, obturator externus, obturator internus, semimenbranosus, semitendinosus, vastus medialis and vastus lateralis/intermedius (Fig. 1). Volume and radiological density of each muscle were measured. The ratio of those of affected limb to healthy limb was calculated. At the latest follow-up, the WOMAC score was collected and a history of falls after surgery was asked. The average follow- up period was 6 years. Comparison of the volume and radiological density of each muscle between affected and healthy limbs was performed using the Wilcoxon signed rank test. Correlations between the volume and radiological density of each muscle and each score of the WOMAC were evaluated with Spearman's correlation coefficient. The volume and radiological density of each muscle between patients with and without a history of falls were compared using Mann-Whitney U test. Results. 13 of 17 muscles showed significant decrease in muscle volume in affected limb compared to healthy limb. The mean muscle atrophy ratio was 18.6±7.1 (SD) % (0–28.3%). Iliacus, psoas, adductors and piriformis showed a significant volume reduction more than 25 %. All 17 muscles showed reduced radiological density along the affected limb compared to the healthy side. The difference was 8.7±4.2 (SD) Hounsfield units (3.2 to 16.4). Gluteus medius and gluteus minimus showed a significant decrease of radiological density more than 15 HU. The radiological density of gluteus minimus showed higher correlation (R>0.7) with physical function scores of WOMAC for descending stairs, rising from sitting, walking on flat surface, going shopping and rising from bed. Seven of 20 patients had a history of falls, who showed significant reduced radiological density of gluteus minimus and obturator internus compared to the 13 patients without a history of falls. Conclusion. Almost all muscles of pelvis and thigh along the affected limb showed marked atrophy and fatty degeneration compared to the healthy side. Especially, the degree of fatty degeneration of gluteus minimus showed significant impacts on postoperative physical function and the risk of falls of patients

Tenotomy of the iliopsoas tendon has been described as an effective procedure to treat refractive groin pain induced by iliopsoas tendinitis. However, the procedure forces the rectus femoris to act as the primary hip flexor and little is known about the long-term effects of this procedure on the peri-articular muscle envelope (PAME). Studies suggest that iliopsoas tenotomy results in atrophy of the iliopsoas and decreased hip flexion strength with poorer outcomes, increasing the susceptibility for secondary tendinopathy. The aim of this study is to describe changes in the PAME following psoas release. All patients who presented for clinical examination at our hospital between 2016 and 2021 were retrospectively reviewed. Patients who presented after psoas tenotomy with groin pain and who were unable to actively lift the leg against gravity, were included. Pelvic MRI was taken. Qualitative muscle evaluation was done with the Quartile classification system. Quantitative muscle evaluation was done by establishing the cross-sectional area (CSA). Two independent observers evaluated the ipsi- and contralateral PAME twice. The muscles were evaluated on the level: iliacus, psoas, gluteus minimus-medius-maximus, rectus femoris, tensor fasciae lata, piriformis, obturator externus and internus. For the qualitative evaluation, the intra- and inter-observer reliability was calculated by using kappastatistics. A Bland-Altman analysis was used to evaluate the intra- and inter-observer reliability for the quantitative evaluation. The Wilcoxon test was used to evaluate the changes between the ipsi- and contra-lateral side. 17 patients were included in the study. Following psoas tenotomy, CSA reduced in the ipsilateral gluteus maximus, if compared with the contralateral side. Fatty degeneration occurred in the tensor fascia latae. Both CSA reduction and fatty degeneration was seen for psoas, iliacus, gluteus minimus, piriformis, obturator externus and internus. No CSA reduction and fatty degeneration was seen for gluteus medius and rectus femoris. Conclusions/Discussion. Following psoas tenotomy, the PAME of the hip shows atrophy and fatty degeneration. These changes can lead to detrimental functional problems and may be associated with debilitating rectus femoris tendinopathy. In patients with psoas tendinopathy, some caution is advised when considering an iliopsoas tenotomy

Purpose of the study: Muscles contract after a full thickness tear their tendon. The muscle then undergoes atrophy and fatty degeneration. These changes produce effects well described by histology, computed tomography and magnetic resonance imaging (MRI). To date however, the correlation of this process with the future conractile force of the muscle and the prognosis after cuff repain has been poorly understood. Material and methods: Thirteen patients with a full thickness tear of the supraspinatus muscle were treated surgically by cuff suture. The shoulders were examined clinically and MRI. During the operation, the supra-scapular nerve was stimulated with a supramaximal voltage to obtain maximal muscle contraction which was measured. Biopsy specimens of the supraspinatus were taken before and after surgical repair in order to determine whether muscle activity during stimulation have any histological impact. The intraoperative measurements were compared with the MRI findings and the physical examination performed preoperative and at six weeks, six months and twelve months after surgery. Results: Maximal force of the supraspinatus muscle was 200N, which is greater than the force of a direct suture repair. The maximal force was clearly correlated with muscle atrophy and fatty degeneration: by surface area, force was 12N/cm. 2. for Goutallier grade 3 and 42 N/m. 2. for grade 0. Five of the thirteen repairs ended with a secondary tear, the muscle in four of the five patients was among the six strongest muscles. The fifth case was the weakest muscle of all. The histological study revealed a larger quantity of lipofuchin in the muscle with atrophy and a change in the fiber structure. Analysis of the results did not demonstrate any lesions caused by the tension during the operation. MRI demonstrated one case of repair without secondary tear, the fatty infiltration had not improved and the atrophy only partially. In muscles with secondary tears, atrophy and fatty degeneration progressed significantly. Discussion and conclusion: There is a risk of rupture of the supraspinatus tendon in the event of muscle atrophy but also for good quality muscle. The capacity of a muscle to develop force strongly depends on the state of atrophy and fatty degeneration. Atrophy can regress after reconstruction without secondary tear, but fatty degeneration is irreversible

Purpose: Centred degeneration of the shoulder joint is defined as a degeneration of the glenohumeral surfaces without ascension of the humeral head. We investigated the influence of partial or full thickness rotator cuff tears and/or fatty degeneration of the supraspinatus on the results of total shoulder arthroplasty. Material and methods: During a multicentric review of 766 cases of centred degeneration of the shoulder joint treated with the Aequalis prosthesis, we identified 555 shoulders in 478 patients with an interpretable preoperative arthroscan. All patients were reviewed with a minimum follow-up of two years (mean 3.6 years). Constant score and radiological findings were recorded. We identified 41 shoulders with partial tears of the supraspinatus and 42 shoulders with full-thickness tears of the supraspinatus alone. Moderate fatty degeneration was observed in 90 shoulders (≤ 2) and severe fatty degeneration of the infraspinatus or the subscapularis (> 2) in 15. We analysed the Constant scores, subjective results, radiological results, and rate of complications in each of these populations. Results: Rotator cuff tears involving the supraspinatus alone did not have a destabilising effect, the head of the humerus did not influence the postoperative result assessed by the overall Constant score, motion in all planes, subjective result, radiological result, or rate of complications. There was no significant difference in complication rate. Presence or not of cuff repair did not influence these results. Inversely, fatty degeneration ≥ 2 involving the infrastpinatus or the subscapularis had a significant effect, decreasing the Constant score, active external rotation, active anterior elevation, and subjective result. On the contrary, it did not influence the radiological results or the rate of complications. Discusssion: This multicentric study confirms that the degenerated shoulder joint can remain centred with a solitary tear of the supraspinatus. This has no effect on the clinical result and does not require repair. Inversely, fatty degeneration is highly predictive of the quality of the final result

Purpose: We examined the long-term effect of the Latarjet-Patte procedure on subscapularis function and trophicity. Material and methods: The series included 102 patients (106 shoulders) reviewed at a mean follow-up of 7.5 years. The subscapularis was opened by dissection along the direction of the fibres in 27 shoulders (group I) and via inverted-L tenotomy in 69 (group II). Duplay and Rowe scores were used to assess clinical outcome. Subscapularis function was measured with the hand-back distance and the Gerber lift-off test in comparison with a control group composed of healthy subjects in order to account for limb dominance. Computed tomography was used to measure fatty degeneration and muscle atrophy. Results: The Duplay and Rowe scores gave 76.4% and 87.7% satisfactory results. The Duplay score was 89.9/100 in group I and 82.1 in group II (p = 0.02). The hand-back distance and muscle force as judged by the lift-off test were statistically different between the dominant and non-dominant sides (p = 0.001). Loss of muscle force was greater for dominant sides in the operated shoulders. The mobility score, the lift-off test, and the hand-back distance were significantly altered in group II patients. Fatty degeneration of the sub-scapularis was greater on the operated side (0.76 vs 0.054) (p = 0.001). It increased with age at surgery and at review (p = 0.0001), for dominant shoulders in group II (1.18 vs 0.12). It affected the Duplay score (p = 0.006), the hand-back distance, and the lift-off test (p = 0.01). Fatty degeneration was greater than 2 in 66% of the shoulders with a poor outcome and persistent apprehension in 35.3%. Subscapular atrophy was greater on the operated side (0.91 vs 1.17) (p = 0.0001) and was statistically correlated with fatty degeneration, the Duplay score, the lift-off test, and the hand-back distance. It was greater in group II (0.71) than in group I (0.2). Discussion: Recovery of muscle force is better for dominant shoulders. Muscle trophicity and function are influenced by subscapular tenotomy that leads to significant loss of internal rotation force, atrophy, and fatty degeneration affecting final long-term outcome. Conclusion: We recommend discission of the subscapularis for coracoid bone block procedures

Background: Many studies have examined magnetic resonance images (MRI) with a view to the anatomy and signaling properties of the intervertebral disc and adjacent tissues in asymptomatic populations. In this study we have examined MRIs of a discrete population of patients undergoing surgery for symptomatic disc herniations. Methods: Sixty patients (aged 23–66 years, mean 41.5±8.4) had sagittal T1 and T2- weighted turbo spin echo imaging of the lumbar spine prior to surgery. One disc was herniated at L2-3, 3 at L3-4, 22 at L4-5 and 31 at L5-S1; 3 patients had herniations at both L4-5 and L5-S1. The images were scored for disc narrowing and signal, degree of anterior and posterior bulging and herniation, and assessed for Modic I and II endplate changes and fatty degeneration within the vertebrae. These were carried out for each of 6 discs (T12-S1) for all patients (ie 360 discs and 720 endplates). Results: There were trends of increasing disc narrowing, disc bulging and fatty degeneration with increasing age in these patients. 83% of patients had disc bulging, 53% had endplate irregularities and 44% had fatty degeneration. There was a significant correlation between patient weight and fatty degeneration. 7.5% of vertebrae (in 22% of patients) demonstrated Modic I changes whilst Modic II changes were seen in 14% of vertebrae (40% of patients). This is considerably higher than the incidence reported in asymptomatic individuals where Modic I changes were seen in 0.7% of vertebrae (3% of individuals) and Modic II changes in 1.9% of vertebrae (10% of individuals). Conclusion: There is a higher incidence of Modic I and II changes in disc herniation patients than in asymptomatic individuals

Massive posterosuperior cuff tears (mRCT) retracted to the glenoid are surgically challenging and often associated with high retear rates. Primary repair is a less-favourable option and other salvage procedures such as SCR and tendon transfers are used. This study presents clinical and radiological outcomes of muscle advancement technique for repair of mRCT. Sixty-one patients (mean age 57±6, 77% males and 23% females) (66 shoulders) underwent all-arthroscopic rotator cuff repair that included supraspinatus and infraspinatus subperiosteal dissection off scapular bony fossae, lateral advancement of tendon laminae, and tension-free double-layer Lasso Loop repair to footprint. Pre-and post-operative range of motion (ROM), cuff strength, VAS, Constant, ASES, and UCLA scores were assessed. Radiologic assessment included modified Patte and Goutallier classifications. All patients had MRI at 6 months to evaluate healing and integrity of repair was assessed using Sugaya classification with Sugaya 4 and 5 considered retears. Advanced fatty degeneration (Goutallier 3-4) was present in 44% and 20% of supraspinatus and infraspinatus. Tendon retraction was to the level of or medial to glenoid in 22%, and just lateral in 66%. 50.8% mRCT extended to teres minor. Subscapularis was partially torn (Lafosse 1-3) in 46% and completely torn (Lafosse 4-5) in 20%. At mean follow-up (52.4 weeks), a significant increase in ROM, Relative Cuff Strength (from 57% to 90% compared to contralateral side), VAS (from 4 ±2.5 to 1±1.7), Constant (50±17.8 to 74 ±13.0), ASES (52 ±17.5 to 87 ±14.9), and UCLA (16± 4.9 to 30 ±4.9) scores were noted. There were six retears (10%), one failure due to P. acnes infection. 93% returned to pre-injury work and 89% of cases returned to pre-injury sport. Satisfaction rate was 96%. Muscle advancement technique for mRCT is a viable option with low retear rates, restoration of ROM, strength, and excellent functional outcomes

Leakage after simple suture repair of rotator cuff tears depends on the overall preoperative fatty degeneration index (FDI) of the muscles and preoperative fatty degeneration (FD) of the infraspinatus. When the FDI is = 2, cuff leakage is always observed after repair. The risk of recurrent tears of the supraspinus is high if the FD of the infraspinatus is > 1. However if the FDI is very low or nil, the rate of recurrent tears is 15%. These tears can be explained by tension on sutures in macroscopically and histologically abnormal tendons. Purpose: The purpose of this study was to determine whether repair of rotator cuff tears using sutures without tension after removal of abnormal tendon stumps, a technique requiring tendon plasty, can improve the leakage rate. Material and methods: Total repair of 24 rotator cuff tears was performed without tension on the sutures after resection of at least one centimetre of the supraspinatus tendon stump. This consecutive series was studied prospectively. The tears involved the supraspinatus and the infraspinatus in ten cases, all three tendons in 13 cases and only the supraspinatus in one case. Mean preoperative FDI was 1.18 (0.5–2.16); pre-operative FD of the infraspinatus was a mean 1.19 (0–2). The supraspinatus stump was resected from the trochiter in 14 cases, on the apex of the head of the humerus in seven and facing the glenoid cavity in three. Repair required translation advancement of the supraspinatus in 24 cases, translation advancement of the infraspinatus in six (associated with a rhomboid flap) and a trapezeal flap in three cases. Postoperative leakage was assessed with arthroscan (n=23) and ultrasonography (n=1) at one year. Results: No leakage was observed in 20 of the 24 cuffs (83%). Recurrent tear of the supraspinatus was observed in three cases and in the supraspinatus and infraspinatus in one case each. The FDI of cuffs with recurrent tears (1.31) was not significantly greater than the FDI of cuffs without leakage (1.15) (p = 0.085). Preoperative FD of the infraspinatus of cuffs with recurrent tears (1.5) was significantly higher than that for cuffs without leakage (1.12) (p = 0.16). For the supraspinatus and the subscapularis, there was no significant difference between preoperative fatty degeneration of cuffs with recurrent tears and cuffs without leakage. The number of repaired tendons had a statistically significant effect (p = 0.012) on postoperative leakage: 23% of the recurrent tears after repair of three tendons showed no leakage compared with 9% after repair of one or two tendons (there was no significant difference for preoperative FDI, p = 0.33). Discussion: Resection of macroscopically abnormal tendon stumps which requires tendinomuscular plasty, gives better anatomic results than simple suture. For an equivalent FDI, this allows fewer cases of leakage (83% without leakage compared with 50% after simple suture). Results were also better for an equivalent number of tendons repaired: 77% and 50% for three tendons and 91% and 55% for two tendons respectively). Conclusion: Despite the almost constant need for plasty, rotator cuff repair using sutures without tension after resection of macroscopically abnormal tendon stumps gives, for an equivalent preoperative degree of fatty degeneration and an equivalent number of tendon repairs, better anatomic results than simple suture

Sub-Acromial Decompression (SAD) for impingement has a failure rate of 5–20%. We used MRI to see whether SAD failure is associated with muscle wasting or fatty degeneration in the rotator cuff. Fifty one patients with impingement were assessed using MRI pre- and post-op. Following arthroscopic SAD, seven patients with cuff tears were excluded. This study reviews the pre-op and 6 month post-op MRIs of the remaining 44 patients (25 males; 19 females) and also 17 additional MRIs obtained at three years post-op. MRI assessment was performed by an experienced radiologist using Zanetti’s muscle bulk assessment with values expressed as standard deviations from an age matched mean and Goutallier’s fatty degeneration assessment graded 0 to 4. There was a wide range of pre-op muscle bulk values (SupraSpinatus minus;2.4 to +3.4; SubScapularis minus;2.1 to +4.8; and InfraSpinatus/ Teres Minor minus;1.1 to +5.7). Comparing post-op with pre-op there was a gradual trend towards a reduced muscle bulk for each muscle after surgery but to a limited extent only (< 0.5SD). Pre-op fatty degeneration of SS and IS was grade 2 in about a half with a mild increase with time post-op (SS pre=50%, 6/12 and 3 years=59%; IS pre=45%, 6/12=43% and 3 years=59%). There was a similar age distribution for grades 1 and 2. Only three of the patients were a clinical failure at 6 months but this increased to five of the 17 patients scanned at 3 years. Predicting these failures was not possible based on the pre-op MRI data. The high initial success of SAD was not accompanied by an overall increase in muscle bulk or quality of the muscle at 6 months. The progressive loss of muscle bulk and quality over 3 years was accompanied by an increased clinical failure rate

Purpose of the study: A statistical analysis of correlations between clinical outcome and anatomic results after arthroscopic repair of rotator cuff tears. Material and methods: This multicentric series of rotator cuff tears was limited to the supraspinatus and infraspinatus. The statistical analysis searched for correlations between the clinical outcome (Constant score) and anatomic results (arthroscan and arthroMRI). The series included 576 patients, mean age 57.7 years, 52%μ males and 60% manual laborers. The tear was limited to the suprapsinatus in 69% of patients, with extension to the upper third of the infraspinatus in 23.5% and all tendons in 7.5%. The supraspinatus tear was distal in 41.7% of patients, intermediary in 44% and retracted in 14.3%. Fatty degeneration of the supraspinatus was noted grade 0 in 59.7%, 1 in 27.1%, 2 in 10.8% and 3 in 2.4%. Results: The Constant score (46.3 preoperatively and 82.7 postoperatively) was strongly correlated with successful repair. The correlation was found for force, motion, and activity, but not for pain. The clinical outcome was correlated with extension, retraction, cleavage, and degeneration of the preoperative injury. The anatomic result was statistically less favorable for older, more extended, retracted, and cleaved tears or tears associated with fatty degeneration. Age was correlated with the extent of the initial tear and also with less favorable clinical and anatomic results. Work accidents were correlated with less favorable clinical outcome. Discussion: The large number of anatomic controls with contrast injection facilitated demonstration of several statistically significant correlations. This enabled disclosure in a single series of evidence confirming earlier reports in the literature: repair of cuff tears improves the overall functional outcome for massive tears; the anatomic result depends on the size of the initial tear; pre-operative fatty degeneration is an important prognostic criteria; cuff healing is age-dependent. Conclusion: Study of anatamoclinical correlations helps guide therapeutic decision making and enables the establishment of reliable prognostic criteria after arthroscopic repair of rotator cuff tears

The function of the upper extremity is highly dependent on correlated motion of the shoulder. The shoulder can be affected by several diseases. The most common are: rotator cuff tear (RCT), shoulder instability, shoulder osteoarthritis and fractures. Rotator cuff disease is a common disorder. It has a high prevalence rate, causing high direct and indirect costs. The appropriate treatment for RCT is debated. The American Academy Orthopaedic Surgeons guidelines state that surgical repair is an option for patients with chronic, symptomatic full-thickness RCT, but the quality of evidence is unconvincing. Thus, the AAOS recommendations are inconclusive. We are performing a randomized controlled trial to compare surgical and conservative treatment of RCT, in term of functional outcomes, rotator cuff integrity, muscle atrophy and fatty degeneration. Shoulder instability occurs when the head of the upper arm bone is forced out of the shoulder socket. Shoulder instabilities have been classified according to the etiology, the direction of instability, or on combinations thereof. The Thomas and Matsen classification, which is currently the most commonly utilized classification, divides shoulder instability events into the traumatic, unidirectional, Bankart lesion, and surgery (TUBS) and the atraumatic, multidirectional, bilateral, rehabilitation, and capsular shift (AMBRI) categories. The acquired instability overstress surgery (AIOS) category was then added. Surgical procedures for shoulder instability includes arthroscopic capsuloplasty, remplissage, bone block procedure or Latarjet procedure. Reverse total shoulder arthroplasty (RTSA) represents a good solution for the management of patients with osteoarthritis or fracture of the proximal humerus, with associated severe osteoporosis and RC dysfunction

The February 2014 Shoulder & Elbow Roundup. 360 . looks at: whether arthroscopic acromioplasty is a cost-effective intervention; shockwave therapy in cuff tear; whether microfracture relieves short-term pain in cuff repair; the promising early results from L-PRF augmented cuff repairs; rehabilitation following cuff repair; supination strength following biceps tendon rupture; whether longer is better in humeral components; fatty degeneration in a rodent model; and the controversial acromioclavicular joint dislocation

Objectives. The objective of this study was to determine if the use of fascia lata as a tendon regeneration guide (placed into the tendon canal following harvesting the semitendinosus tendon) would improve the incidence of tissue regeneration and prevent fatty degeneration of the semitendinosus muscle. Materials and Methods. Bilateral semitendinosus tendons were harvested from rabbits using a tendon stripper. On the inducing graft (IG) side, the tendon canal and semitendinosus tibial attachment site were connected by the fascia lata, which was harvested at the same width as the semitendinosus tendon. On the control side, no special procedures were performed. Two groups of six rabbits were killed at post-operative weeks 4 and 8, respectively. In addition, three healthy rabbits were killed to obtain normal tissue. We evaluated the incidence of tendon tissue regeneration, cross-sectional area of the regenerated tendon tissue and proportion of fatty tissue in the semitendinosus muscle. Results. At post-operative week 8, the distal end of the regenerated tissue reached the vicinity of the tibial insertion on the control side in two of six specimens. On the IG side, the regenerated tissue maintained continuity with the tibial insertion in all specimens. The cross-sectional area of the IG side was significantly greater than that of the control side. The proportion of fatty tissue in the semitendinosus muscle on the IG side was comparable with that of the control side, but was significantly greater than that of the normal muscle. Conclusions. Tendon tissue regenerated with the fascia lata graft was thicker than naturally occurring regenerated tissue. However, the proportion of fatty tissue in the semitendinosus muscle was greater than that of normal muscle. Cite this article: K. Tabuchi, T. Soejima, H. Murakami, K. Noguchi, N. Shiba, K. Nagata. Inducement of tissue regeneration of harvested hamstring tendons in a rabbit model. Bone Joint Res 2016;5:247–252. DOI: 10.1302/2046-3758.56.2000585

The February 2014 Research Roundup. 360 . looks at: blood supply to the femoral head after dislocation; diabetes and hip replacement; bone remodelling over two decades following hip replacement; sham surgery as good as arthroscopic meniscectomy; distraction in knee osteoarthritis; whether joint replacement prevent cardiac events; tranexamic acid and knee replacement haemostasis; cartilage colonisation in bipolar ankle grafts; CTs and proof of fusion; atorvastatin for muscle re-innervation after sciatic nerve transection; microfracture and short-term pain in cuff repair; promising early results from L-PRF augmented cuff repairs; and fatty degeneration in a rodent model

Purpose of the study: Four elements differentiate myotendinous tears of the infraspinatus from other rotator cuff tears: the tendon insertion on the trochiter and the joint capsule are spared; the onset in characterized by intense muscle oedema followed at 6 to 12 months by severe and definitive fatty degeneration. Material and method: Fifty-nine myotendinous tears of the infraspinatus were collected prospectively from 1993 to 2007. Female gender predominated (58%); trauma was noted at onset in 22% of the shoulders and the mean age of discovery was 48.9 years. Twenty-nine shoulders were seen at the acute phase with significant muscle oedema recognized on the MRI T2 Fat Sat sequence. A second group of 30 patients had grade 4 fatty infiltration of the infraspinatus without full thickness cuff tears. The EMG was available for 23 shoulders and was normal in all, ruling out a neurological cause. Associated lesions of the supraspinatus and infraspinatus tendons were: tendon calcification (61%) and partial tears at the acute phase (21%) and chronic phase (70%) suggesting a degenerative cause. Results: Twenty-four patients underwent surgery and 35 had a medical treatment. At mean 46 months follow-up (range 12–125) the Constant score improved from 51.7 to 69.4 points (p< 0.0001). There was no different statistically between the operated and non-operated patients (p=0.325). All patients seen at the acute phase of the oedema progressed to complete grade 4 fatty degeneration of the muscle, irrespective of the treatment delivered. Discussion: Early diagnosis of this lesion can be achieved with T2 Fat Sat MRI sequences. Arthroscopic repair to tighten the infraspinatus muscle could avoid the irremediable degeneration with total loss of muscle function

Although interlaminar endoscopic lumbar discectomy (IELD) is considered to be less invasive than microscopic lumbar discectomy (MLD) in treatment of lumbar herniated nucleus pulposus, the radiologic change of multifidus muscles by each surgery has rarely been reported. The aim of the present study was to compare the quantitative and qualitative changes of multifidus muscles between two surgical approaches and to analyze the correlation between various parameters of multifidus muscles and long term surgical outcome. 21 patients who received MLD and 18 patients who received IELD in a single tertiary hospital were enrolled and their preoperative, postoperative (≤15 days), and follow-up (≥6 months) MRIs were analyzed. The cross-sectional area (CSA) and fatty degeneration rate (FD) were quantitatively estimated at the level of surgery. The correlations among CSA, FD, body mass index, follow-up visual analogue scale(VAS) and Oswestry Disability Index(ODI) were assessed. Mean intervals of postoperative MRI and follow-up MRI from surgery were 3.0±3.7 days and 14.5±10.7 months, respectively. During the follow-up period, VAS was improved from 7.1±1.3 to 2.1±1.8 in MLD and from 8.2±1.4 to 2.2±1.8 in IELD. In cases of MLD, comparing with preoperative MRI, ipsilateral CSA was significantly increased in postoperative MRI (795.6mm. 2. vs. 906.5mm. 2. , p<0.01), but it was not significantly different in follow-up MRI (795.6mm. 2. vs. 814.4mm. 2. , p=1.00). However, in case of IELD, the ipsilateral CSAs in preoperative, postoperative, and follow-up periods were 892.0 mm. 2. , 909.3 mm. 2. , and 900.3 mm. 2. , respectively. These changes were not significant over time (p=0.691). The ipsilateral FDs were not significantly changed between preoperative and follow-up periods in both MLD (21.4% vs. 20.9%, p=0.81) and IELD groups (23.5% vs. 21.8%, p=0.19). The increment of ipsilateral CSA had significant correlations with follow-up ODI (r=−0.368, p=0.02). Comparing with IELD, MLD induced more surgical trauma on multifidus muscle in postoperative period, but the muscular damage was recovered in follow-up period. IELD can minimize surgical trauma on multifidus muscle showing similar pain relief as MLD. Favorable surgical outcome in follow-up period may be related to increment of multifidus muscle volume. Figure 1. (A-C) The multifidus muscles in preoperative, postoperative, and follow-up periods, respectively, in patient with MLD. Comparing with preoperative period, the CSA of right multifidus muscle (ipsilateral side) was increased in postoperative period, but recovered in follow-up period. (D-F) The multifidus muscle in preoperative, postoperative, and follow-up periods, respectively, in patient with IELD. The CSA of left multifidus muscles (ipsilateral side) was not significantly changed over time. Comparing preoperative MRIs with follow-up MRIs, the FDs of multifidus muscles were not significantly changed regardless of surgical technique. Figure 2. The CSA was measured by marking region of interest (ROI) and FD was measured by calculating the rate of pixels beyond the threshold in ROI. All measurements were performed using ImageJ software (version 1.52a, National Institutes of Health, Bethesda, Maryland, USA). For any figures or tables, please contact the authors directly

Purpose of the study: When repairing rotator cuff tears, injury to the infraspinatus is generally a posterior extension of a supraspinatus tear. The description of isolated tears of the infraspinatus has not been to our knowledge reported in the literature. We report a series of 13 cases with more than one year follow-up. Material and methods: Thirteen patients underwent surgery for an isolated tear of the infraspinatus between 1995 and 2004. There were ten men and three women. Mean age at surgery was 47 years (range 34–62). The right shoulder was involved in seven of the thirteen cases, and the dominant shoulder in eight. A progressive onset was observed in eleven patients and nine had a history of treated calcified tendinopathy. Clinically, pain was the predominant symptom. The Jobe test was deficient in all patients as was external rotation (except one patient). The preoperative Constant score was 70 (range 62–87). X-rays revealed type C posterior calcification in nine patients. A full-thickness tear was observed in seven cases, a partial deep tear in three, and a partial superficial tear in three. Isolated fatty degeneration of the infraspinatus noted Goutallier grade 2 or greater was observed in seven patients. Open surgical repair was preformed in all patients. Results: Mean time to revision was 29 months (range 12–82). Subjectively, six patients were very satisfied, six were satisfied, and one was disappointed (failure by secondary tear). Two shoulder-hand syndromes were noted in the postoperative period. At last follow-up, the Constant score was 83.5 (range 64–97). All patients except one were satisfied with pain relief but the lack of force was significant. Discussion and conclusion: Isolated tears of the infra-spinatus are rare, but there is a notable relationship with calcifying tendinopathy of the same tendon. Repair should be undertaken before the development of fatty degeneration in order to improve the chances of force recovery

Purpose of the study: The objective of this study was to identify clinical and anatomic factors which could affect the outcome of tendon healing after arthroscopic repair of rotator cuff tears. Material and methods: This prospective cohort study included 122 patients who underwent arthroscopic treatment between May 1999 and September 2002. One hundred twelve patients (114 shoulders) were reviewed (93.4%). Mean age at surgery was 61 years. An arthroscan (78% of patients) or magnetic resonance imaging (MRI) were performed six months postoperatively. Mean follow-up was 24 months (range 13–46 months). Results: Rotator cuff tears healed completely in 64% of the shoulders (n=73) and partially in 7% (n=8). No healing was observed in 29% (n=33). The Constant score was 49.8 preoperatively and 82.4 at last follow-up (p< 0.0001). Cuff healing improved clinical outcome with a Constant score of 85 points versus 77, particularly for force, 14.5 points versus 10 without healing. Four factors were statistically predictive of tendon healing: duration from symptom onset to operation (24 months for healed tears versus 37 months, p< 0.05); age at cuff repair (81% healed tears in patients aged less than 50 years versus 50% for patients aged over 65 years, p< 0.002); sagittal extension of the rotator interval or extension to the upper third of the infrascapularis (45% healed tears versus 79% without anterior extension, p< 0.0001); fatty degeneration (69% of healed tears for Goutallier grade 0 versus 38% for grade 1 and 2, p< 0.01). Conclusion: This study demonstrated that four factors can predict tendon healing: time to treatment, age at surgery, anterior extension of the tear, fatty degeneration