Aims

We aimed to develop a gene signature that predicts the occurrence of postmenopausal osteoporosis (PMOP) by studying its genetic mechanism.

Aims

The decrease in the number of satellite cells (SCs), contributing to myofibre formation and reconstitution, and their proliferative capacity, leads to muscle loss, a condition known as sarcopenia. Resistance training can prevent muscle loss; however, the underlying mechanisms of resistance training effects on SCs are not well understood. We therefore conducted a comprehensive transcriptome analysis of SCs in a mouse model.

Objectives. Traumatic brachial plexus injury causes severe functional impairment of the arm. Elbow flexion is often affected. Nerve surgery or tendon transfers provide the only means to obtain improved elbow flexion. Unfortunately, the functionality of the arm often remains insufficient. Stem cell therapy could potentially improve muscle strength and avoid muscle-tendon transfer. This pilot study assesses the safety and regenerative potential of autologous bone marrow-derived mononuclear cell injection in partially denervated biceps. Methods. Nine brachial plexus patients with insufficient elbow flexion (i.e., partial denervation) received intramuscular escalating doses of autologous bone marrow-derived mononuclear cells, combined with tendon transfers. Effect parameters included biceps biopsies, motor unit analysis on needle electromyography and computerised muscle tomography, before and after cell therapy. Results. No adverse effects in vital signs, bone marrow aspiration sites, injection sites, or surgical wound were seen. After cell therapy there was a 52% decrease in muscle fibrosis (p = 0.01), an 80% increase in myofibre diameter (p = 0.007), a 50% increase in satellite cells (p = 0.045) and an 83% increase in capillary-to-myofibre ratio (p < 0.001) was shown. CT analysis demonstrated a 48% decrease in mean muscle density (p = 0.009). Motor unit analysis showed a mean increase of 36% in motor unit amplitude (p = 0.045), 22% increase in duration (p = 0.005) and 29% increase in number of phases (p = 0.002). Conclusions. Mononuclear cell injection in partly denervated muscle of brachial plexus patients is safe. The results suggest enhanced muscle reinnervation and regeneration. Cite this article: Bone Joint Res 2014;3:38–47

Aims. Improvements in the evaluation of outcomes following peripheral nerve injury are needed. Recent studies have identified muscle fatigue as an inevitable consequence of muscle reinnervation. This study aimed to quantify and characterize muscle fatigue within a standardized surgical model of muscle reinnervation. Patients and Methods. This retrospective cohort study included 12 patients who underwent Oberlin nerve transfer in an attempt to restore flexion of the elbow following brachial plexus injury. There were ten men and two women with a mean age of 45.5 years (27 to 69). The mean follow-up was 58 months (28 to 100). Repeated and sustained isometric contractions of the elbow flexors were used to assess fatigability of reinnervated muscle. The strength of elbow flexion was measured using a static dynamometer (KgF) and surface electromyography (sEMG). Recordings were used to quantify and characterize fatigability of the reinnervated elbow flexor muscles compared with the uninjured contralateral side. Results. The mean peak force of elbow flexion was 7.88 KgF (. sd. 3.80) compared with 20.65 KgF (. sd . 6.88) on the contralateral side (p < 0.001). Reinnervated elbow flexor muscles (biceps brachialis) showed sEMG evidence of fatigue earlier than normal controls with sustained (60-second) isometric contraction. Reinnervated elbow flexor muscles also showed a trend towards a faster twitch muscle fibre type. Conclusion. The assessment of motor outcomes must involve more than peak force alone. Reinnervated muscle shows a shift towards fast twitch fibres following reinnervation with an earlier onset of fatigue. Our findings suggest that fatigue is a clinically relevant characteristic of reinnervated muscle. Adoption of these metrics into clinical practice and the assessment of outcome could allow a more meaningful comparison to be made between differing forms of treatment and encourage advances in the management of motor recovery following nerve transfer. Cite this article: Bone Joint J 2019;101-B:867–871

Aims

The aim of this study is to provide a detailed description of cases combining bridging patch repair with artificial ligament “internal brace” reinforcement to treat irreparable massive rotator cuff tears, and report the preliminary results.

We compared the outcome of peri-operative humeral condylar fractures in patients undergoing a Coonrad-Morrey semiconstrained total elbow replacement with that of patients with rheumatoid arthritis undergoing the same procedure without fractures. In a consecutive series of 40 elbows in 33 patients, 13 elbows had a fracture in either condyle peri-operatively, and 27 elbows were intact. The fractured condyle was either fixed internally or excised. We found no statistical difference in the patients’ background, such as age, length of follow-up, immobilisation period, Larsen’s radiological grade, or Steinbrocker’s stage and functional class. There was also no statistical difference between the groups in relation to the Mayo Elbow Performance Score, muscle strength, range of movement, or radiolucency around the implants at a mean of 4.8 years (1.1 to 8.0) follow-up. We conclude that fractured condyles can be successfully treated with either internal fixation or excision, and cause no harmful effect

Opinion varies as to the incidence of nerve lesions in anterior dislocation of the shoulder after low-velocity trauma. Most studies are retrospective or do not use EMG. We have investigated the incidence and the clinical consequences of nerve lesions in a prospective study by clinical and electrophysiological examination. Axonal loss was seen in 48% of 77 patients. The axillary nerve was most frequently involved (42%). Although recovery as judged by EMG and muscle strength was almost complete, function of the shoulder was significantly impaired in patients with lesions of the axillary and suprascapular nerves. Unfavourable prognostic factors are increasing age and the presence of a haematoma. It is not necessary to carry out EMG routinely; an adequate programme of physiotherapy is important. In patients with a severe paresis, EMG is essential after three weeks

We report a review of 54 patients with chronic anterior cruciate ligament rupture treated by patellar-quadriceps tendon graft augmented with polypropylene braid (Kennedy-LAD). The femoral placement of the graft was randomised to either a modified over-the-top (OTT) or a tunnel position obtained by an isometric drill guide (ISO). At the two-year follow-up both procedures had resulted in improvement of subjective knee function and activity level. Stereoradiographic measurements showed reduction of anteroposterior laxity to near normal in about one-third of the patients, but muscle strength and objective functional performance showed little or no changes. The OTT group had better subjective knee function. We were unable to confirm the theoretical advantages of the use of the drill guide, partly because it provided a tibial tunnel which was too anterior

We performed bilateral femoral shortening operations on 15 skeletally mature patients (11 women and four men). Their mean height pre-operatively was 193.5 cm and they were shortened by 5 to 9 cm. We used a subtrochanteric Z-osteotomy with an AO condylar plate in 11 patients, and mid-diaphyseal osteotomy with an intramedullary locking nail in four. After an average follow-up of 8.1 years, isokinetic muscle testing showed that muscle strength was reduced bilaterally in five patients. The strength ratio between hamstrings and quadriceps muscles was normal in all those treated by subtrochanteric shortening; in those shortened at the mid-shaft the quadriceps was relatively weaker. The result was rated as excellent by 11 patients, very good by three, and good by one

1. The importance of accurate methods of measuring the strength of muscles and the amplitude of joint movements in man, both in clinical fields and as criteria of normal function, is discussed. 2. The advantages and disadvantages of subjective and objective methods are reviewed. 3. The main types of apparatus used for the assessment of muscle strength in both normal and clinical conditions are described. A dynamometer of the strain-gauge type is recommended. 4. Methods of measuring the amplitude of movements in man are also described. The protractor type arthrometer is thought to be the most suitable for routine clinical work, but for research purposes a radiographic method may be preferable. 5. The following factors, which must be considered if the measurements taken are to be of greatest use, are discussed: posture, test procedure, standards for comparison, nomenclature and normal variability

In order to investigate the difficulty of quadriceps training in the presence of an effusion into the knee we examined 13 patients with chronic effusions by recording isometric muscle strength. Maximal strength was markedly lower in the presence of an effusion, and aspiration of the effusion produced a 13.6% increase in strength (p less than 0.01). A further, small increase of 8% was recorded after intra-articular lignocaine injection. Isometric strength and surface integrated EMG correlated well in six patients. Two reflex mechanisms seem to inhibit quadriceps innervation in the presence of a persistent knee effusion, one mediated by pressure sensitive receptors, the other still unknown. Joint aspiration and systemic or intra-articular anti-inflammatory drug treatments are advised before any programme of quadriceps training to allow maximum effects to be achieved

We report the results in 33 patients who had nerve grafting of the axillary or the suprascapular nerve or of both. There were 32 men and one woman; their mean age was 21 years and the average interval between injury and operation was three months. At a mean follow-up of 27 months, the deltoid had recovered to M3 or better in 23 of 30 patients (77%) and the infraspinatus in 18 of 25 patients (72%). Shoulder elevation had reached 120° or more in 27 patients (82%), with external rotation of 30° or more in 27 (82%). Twenty-six patients (79%) could reach to the top of their head with their hand. Recovery of muscle strength, range of movement and shoulder function were satisfactory when surgery was performed within four months of the injury. Early exploration and nerve grafting can lead to a good functional recovery, but thorough exploration and careful repair of both nerves are essential

The advantages and disadvantages of endoscopic compared with open carpal tunnelreleasearecontroversial. We have performed a prospective, randomised, blinded assessment in a district general hospital in order to determine if there was any demonstrable advantage in undertaking either technique. Twenty-five patients with confirmed bilateral idiopathic carpal tunnel syndrome were randomised to undergo endoscopic release by the single portal Agee technique to one hand and open release to the other. Independent preoperative and postoperative assessment was undertaken by a hand therapist who was blinded to the type of treatment. Follow-up was for 12 months. The operating time was two minutes shorter for the open technique (p < 0.005). At all stages of postoperative assessment, the endoscopic technique had no significant advantages in terms of return of muscle strength and assessment of hand function, grip strength, manual dexterity or sensation. In comparison with open release, single-portal endoscopic carpal tunnel release has a similar incidence of complications and a similar return of hand function, but is a slightly slower technique to undertake

We compared two methods of reconstruction of the abductor mechanism in 15 patients after prosthetic replacement of the upper femur, to assess abductor strength and function. Six patients in group I had direct fixation of the gluteus medius tendon and a segment of the original bone to the prosthesis. Nine patients in group 2 had the abductor tendon fixed to the iliotibial band. We assessed clinical function, isometric muscle strength and muscle cross-sectional area for each patient. The patients in group 1 had better clinical and functional results (p = 0.059), with average peak torques for hip abduction of 92% of that in the non-operated leg in group 1, and of 57% in group 2. Group 1 had a mean muscle cross-sectional area of 69% and a mean value of strength per cross-sectional area of 134% when compared with the control side. The respective values for group 2 were 52% and 91%. Direct fixation of the abductor muscles to the prostheses gave improved function and higher isometric abductor muscle force

Aims

The outcome following the development of neurological complications after corrective surgery for scoliosis varies from full recovery to a permanent deficit. This study aimed to assess the prognosis and recovery of major neurological deficits in these patients, and to determine the risk factors for non-recovery, at a minimum follow-up of two years.

Recognized anatomic variations that lead to patella instability include patella alta and trochlea dysplasia. Lateralization of the extensor mechanism relative to the trochlea is often considered to be a contributing factor; however, controversy remains as to the degree this contributes to instability and how this should be measured. As the tibial tuberosity-trochlear groove (TT-TG) is one of most common imaging measurements to assess lateralization of the extensor mechanism, it is important to understand its strengths and weaknesses. Care needs to be taken while interpreting the TT-TG value as it is affected by many factors. Medializing tibial tubercle osteotomy is sometimes used to correct the TT-TG, but may not truly address the underlying anatomical problem. This review set out to determine whether the TT-TG distance sufficiently summarizes the pathoanatomy, and if this assists with planning of surgery in patellar instability.

Cite this article: Bone Jt Open 2022;3(3):268–274.

We have studied, prospectively, 116 patients with motor deficits associated with herniation of a lumbar disc who underwent microdiscectomy. They were studied during the first six months and at a mean of 6.4 years after surgery. Before operation, muscle weakness was mild (grade 4) in 67% of patients, severe (grade 3) in 21% and very severe (grade 2 or 1) in 12%. The muscle which most frequently had severe or very severe weakness was extensor hallucis longus, followed in order by triceps surae, extensor digitorum communis, tibialis anterior, and others. At the latest follow-up examination, 76% of patients had complete recovery of strength. Persistent weakness was found in 16% of patients who had had a mild preoperative deficit and in 39% of those with severe or very severe weakness. Muscle strength was graded 4 in all patients with persistent weakness, except for four with a very severe preoperative deficit affecting the L5 or S1 nerve root. They showed no significant recovery. Excluding this last group, the degree of recovery of motor function was inversely related to the preoperative severity and duration of muscle weakness. The patients’ subjective functional capacity was not directly related to the degree of recovery except in those with persistent severe or very severe deficit

The loss of full muscle activation contributes to weakness of the quadriceps muscle in patients with deficiency of the anterior cruciate ligament (ACL). We examined whether a deficit of voluntary activation (VA) of the quadriceps muscle can be reversed by reconstruction of the ACL and assessed its influence on muscle strength and clinical parameters. We evaluated 12 male subjects with an isolated tear of the ACL and 12 matched control subjects before operation and two years after reconstruction of the ACL. Assessment included measurements of isometric knee-extension torque at maximal voluntary contraction (MVC force), knee stability tests, the International Knee Ligament Standard Evaluation Form and the Tegner activity score. A sensitive method of twitch interpolation was used to quantify the VA and to calculate true muscle force. Before operation we found a deficit of VA on both the injured (mean ±SEM 74.9 ± 3.5%) and the uninjured side (74.6 ± 3.0%) in comparison with the control group (91 ± 0.9%). Two years after reconstruction of the ACL the VA improved significantly on both sides but remained less than that of the controls. Correlation analysis revealed an improvement of the VA in patients who returned to a higher level of activity. The deficit of true muscle force, however, persisted regardless of the clinical outcome and ligament stability