Lesser tuberosity osteotomy for total shoulder arthroplasty. Surgical technique

BACKGROUND: Recent studies have suggested that tenotomy and repair of the subscapularis tendon carried out for anterior approaches to the shoulder can be followed by failure of the tendon repair and by changes resulting in permanent loss of subscapularis function. We hypothesized that release of the subscapularis with use of a superficial osteotomy of the lesser tuberosity followed by repair of the two opposing bone surfaces would lead to consistent bone-to-bone healing, which would be possible to monitor radiographically, and would lead to satisfactory clinical and structural outcomes. METHODS: Thirty-nine shoulders in thirty-six consecutive patients who, at an average age of fifty-seven years, had undergone total shoulder replacement through an anterior approach involving an osteotomy of the lesser tuberosity were evaluated at an average of thirty-nine months. Assessment included a standardized interview and physical examination, scoring according to the system described by Constant and Murley, and imaging with conventional radiography and computed tomography to assess healing of the osteotomy site and changes in the subscapularis. RESULTS: The osteotomized tuberosity fragment healed in an anatomical position in all shoulders, and no cuff tendon ruptures were observed. At the time of follow-up, thirty-three (89%) of thirty-seven shoulders evaluated with a belly-press test had a negative result and twenty-seven (75%) of thirty-six shoulders evaluated with a lift-off test had an unequivocally normal result. Fatty infiltration of the subscapularis muscle increased after the operation (p < 0.0001) and was at least stage two in eleven (32%) of thirty-four shoulders. The fatty infiltration had progressed by one stage in eight (24%) of the thirty-four shoulders, by two stages in five shoulders (15%), and by three stages in two shoulders (6%). CONCLUSIONS: Osteotomy of the lesser tuberosity provides an easy anterior approach for total shoulder replacement and is followed by consistent bone-to-bone healing, which can be monitored, and good subscapularis function. In the presence of documented anatomical healing of the osteotomy site, postoperative fatty infiltration of the subscapularis muscle remains unexplained and needs to be investigated further as it is associated with a poorer clinical outcome.

Long-term outcome after structural failure of rotator cuff repairs

BACKGROUND: In a previous study, twenty consecutive patients with a rerupture of the rotator cuff, as documented with magnetic resonance imaging, were found to have significantly less pain and better function and strength, compared with the preoperative state, at 3.2 years postoperatively. It was the purpose of this study to determine the clinical and structural outcomes of these reruptures in the same twenty patients after a longer period of follow-up. METHODS: At a mean of 7.6 years postoperatively, the twenty patients were reexamined clinically and with standard radiographs and magnetic resonance imaging with use of the same clinical, radiographic, and magnetic resonance imaging criteria as were utilized in the review at 3.2 years. The mean age at the time of final follow-up was sixty-six years. RESULTS: Nineteen of the twenty patients continued to be either very satisfied or satisfied with the outcome. The relative Constant score averaged 88% and was not significantly different from the score at 3.2 years, which averaged 83%. The mean scores for pain, function, and strength also had not changed significantly. Overall, the twenty reruptures had not increased in size, and eight of them had healed structurally at the time of the 7.6-year follow-up. Seven of these eight reruptures had been of the supraspinatus tendon only, and seven had been smaller than 400 mm(2) at 3.2 years. Twelve reruptures persisted, and five were larger than the preoperative tear. Fatty infiltration of the infraspinatus muscle progressed significantly (p = 0.015) and the acromiohumeral distance decreased significantly (p = 0.006) between the two follow-up periods. Neither fatty infiltration of the supraspinatus and subscapularis muscles nor glenohumeral osteoarthritis progressed significantly. CONCLUSIONS: At an average of 7.6 years, the clinical outcomes after structural failure of rotator cuff repairs remained significantly improved over the preoperative state in terms of pain, function, strength, and patient satisfaction. Overall, the reruptures that had been present at 3.2 years did not increase in size. We also found that reruptures of the supraspinatus that had been smaller than 400 mm(2) had the potential to heal.

Multilineage differentiation potential of equine blood-derived fibroblast-like cells

Tissue engineering (TE) has emerged as a promising new therapy for the treatment of damaged tissues and organs. Adult stem cells are considered as an attractive candidate cell type for cell-based TE. Mesenchymal stem cells (MSC) have been isolated from a variety of tissues and tested for differentiation into different cell lineages. While clinical trials still await the use of human MSC, horse tendon injuries are already being treated with autologous bone marrow-derived MSC. Given that the bone marrow is not an optimal source for MSC due to the painful and risk-containing sampling procedure, isolation of stem cells from peripheral blood would bring an attractive alternative. Adherent fibroblast-like cells have been previously isolated from equine peripheral blood. However, their responses to the differentiation conditions, established for human bone marrow MSC, were insufficient to fully confirm their multilineage potential. In this study, differentiation conditions were optimized to better evaluate the multilineage capacities of equine peripheral blood-derived fibroblast-like cells (ePB-FLC) into adipogenic, osteogenic, and chondrogenic pathways. Adipogenic differentiation using rabbit serum resulted in a high number of large-size lipid droplets three days upon induction. Cells' expression of alkaline phosphatase and calcium deposition upon osteogenic induction confirmed their osteogenic differentiation capacities. Moreover, an increase of dexamethasone concentration resulted in faster osteogenic differentiation and matrix mineralization. Finally, induction of chondrogenesis in pellet cultures resulted in an increase in cartilage-specific gene expression, namely collagen II and aggrecan, followed by protein deposition after a longer induction period. This study therefore demonstrates that ePB-FLC have the potential to differentiate into adipogenic, osteogenic, and chondrogenic mesenchymal lineages. The presence of cells with confirmed multilineage capacities in peripheral blood has important clinical implications for cell-based TE therapies in horses.

Correlation of atrophy and fatty infiltration on strength and integrity of rotator cuff repairs: a study in thirteen patients

In 13 patients, the development of supraspinatus muscle atrophy and fatty infiltration after rotator cuff tendon repair was quantified prospectively via magnetic resonance imaging. Intraoperative electrical nerve stimulation at repair showed that the maximal supraspinatus tension (up to 200 N) strongly correlated with the anatomic cross-sectional muscle area and with muscle fatty infiltration (ranging from 12 N/cm(2) in Goutallier stage 3 to 42 N/cm(2) in Goutallier stage 0). Within 1 year after successful tendon repair (n = 8), fatty infiltration did not recover, and atrophy improved partially at best; however, if the repair failed (n = 5), atrophy and fatty infiltration progressed significantly. The ability of the rotator cuff muscles to develop tension not only correlates with their atrophy but also closely correlates with their degree of fatty infiltration. With current repair techniques, atrophy and fatty infiltration appear to be irreversible, despite successful tendon repair. Unexpectedly, not only weak but also very strong muscles are at risk for repair failure.

The "flap-shaft" prosthesis for insensate feet with Chopart or Lisfranc amputations

BACKGROUND: The inevitable detachment of tendons and the loss of the forefoot in Chopart and Lisfranc amputations result in equinus and varus of the residual foot. In an insensate foot these deformities can lead to keratotic lesions and ulcerations. The currently available prostheses cannot safely counteract the deforming forces and the resulting complications. METHODS: A new below-knee prosthesis was developed, combining a soft socket with a rigid shaft. The mold is taken with the foot in the corrected position. After manufacturing the shaft, the lateral third of the circumference of the shaft is cut away and reattached distally with a hinge, creating a lateral flap. By closing this flap the hindfoot is gently levered from the varus position into valgus. Ten patients (seven amputations at the Chopart-level, three amputations at the Lisfranc-level) with insensate feet were fitted with this prosthesis at an average of 3 (range 1.5 to 9) months after amputation. The handling, comfort, time of daily use, mobility, correction of malposition and complications were recorded to the latest followup (average 31 months, range 24 to 37 months after amputation). RESULTS: Eight patients evaluated the handling as easy, two as difficult. No patient felt discomfort in the prosthesis. The average time of daily use was 12 hours, and all patients were able to walk. All varus deformities were corrected in the prosthesis. Sagittal alignment was kept neutral. Complications were two minor skin lesions and one small ulcer, all of which responded to conservative treatment, and one ulcer healed after debridement and lengthening of the Achilles tendon. CONCLUSIONS: The "flap-shaft" prosthesis is a valuable option for primary or secondary prosthetic fitting of Chopart-level and Lisfranc-level amputees with insensate feet and flexible equinus and varus deformity at risk for recurrent ulceration. It provided safe and sufficient correction of malpositions and enabled the patients to walk as much as their general condition permitted.

Traumatische chronische Instabilität des proximalen Tibiofibulargelenkes [Traumatic chronic instability of the proximal tibiofibular joint]

The rare condition of chronic instability of the proximal tibiofibular joint can be of traumatic or idiopathic origin and can lead to secondary arthritis. After conservative treatment for 6 months and persistent pain, operative treatment should be considered. We present a case of traumatic instability, ligament reconstruction with a part of the biceps femoris tendon, and postoperative return to full and painless sport activities.

The clinical and structural long-term results of open repair of massive tears of the rotator cuff

BACKGROUND: At a mean follow-up of 3.1 years, twenty-seven consecutive repairs of massive rotator cuff tears yielded good and excellent clinical results despite a retear rate of 37%. Patients with a retear had improvement over the preoperative state, but those with a structurally intact repair had a substantially better result. The purpose of this study was to reassess the same patients to determine the long-term functional and structural results. METHODS: At a mean follow-up interval of 9.9 years, twenty-three of the twenty-seven patients returned for a review and were examined clinically, radiographically, and with magnetic resonance imaging with use of a methodology identical to that used at 3.1 years. RESULTS: Twenty-two of the twenty-three patients remained very satisfied or satisfied with the result. The mean subjective shoulder value was 82% (compared with 80% at 3.1 years). The mean relative Constant score was 85% (compared with 83% at 3.1 years). The retear rate was 57% at 9.9 years (compared with 37% at 3.1 years; p = 0.168). Patients with an intact repair had a better result than those with a failed reconstruction with respect to the mean absolute Constant score (81 compared with 64 points, respectively; p = 0.015), mean relative Constant score (95% and 77%; p = 0.002), and mean strength of abduction (5.5 and 2.6 kg; p = 0.007). The mean retear size had increased from 882 to 1164 mm(2) (p = 0.016). Supraspinatus and infraspinatus muscle fatty infiltration had increased (p = 0.004 and 0.008, respectively). Muscles with torn tendons preoperatively showed more fatty infiltration than muscles with intact tendons preoperatively, regardless of repair integrity. Shoulders with a retear had a significantly higher mean acromion index than those without retear (0.75 and 0.65, respectively; p = 0.004). CONCLUSIONS: Open repair of massive rotator cuff tears yielded clinically durable, excellent results with high patient satisfaction at a mean of almost ten years postoperatively. Conversely, fatty muscle infiltration of the supraspinatus and infraspinatus progressed, and the retear size increased over time. The preoperative integrity of the tendon appeared to be protective against muscle deterioration. A wide lateral extension of the acromion was identified as a previously unknown risk factor for retearing.

Prediction of spatial orientation and morphology of calcaneonavicular coalitions

BACKGROUND: Calcaneonavicular coalitions (CNC) have been reported to be associated with anatomical aberrations of either the calcaneus and/or navicular bones. These morphological abnormalities may complicate accurate surgical resection. Three-dimensional analysis of spatial orientation and morphological characteristics may help in preoperative planning of resection. MATERIALS AND METHODS: Sixteen feet with a diagnosis of CNC were evaluated by means of 3-D CT modeling. Three angles were defined that were expressed in relation to one reproducible landmark (lateral border of the calcaneus): the dorsoplantar inclination, anteroposterior inclination, and socket angle. The depth and width of the coalitions were measured and calculated to obtain the estimated contact surface. Three-dimensional reconstructions of the calcanei served to evaluate the presence, distortion or absence of the anterior calcaneal facet and presence of a navicular beak. The interrater correlations were assessed in order to obtain values for the accuracy of the measurement methods. Sixteen normal feet were used as controls for comparison of the socket angle; anatomy of the anterior calcaneal facet and navicular beak as well. RESULTS: The dorsoplantar inclination angle averaged 50 degrees (+/-17), the anteroposterior inclination angle 64 degrees (+/-15), and the pathologic socket angle 98 degrees (+/-11). The average contact area was 156 mm(2). Ninety-four percent of all patients in the CNC group revealed a plantar navicular beak. In 50% of those patients the anterior calcaneal facet was replaced by the navicular portion and in 44% the facet was totally missing. In contrast, the socket angle in the control group averaged 77 degrees (+/-18), which was found to be statistically different than the CNC group (p = 0.0004). Only 25% of the patients in the control group had a plantar navicular beak. High, statistically significant interrater correlations were found for all measured angles. CONCLUSION: Computer-aided CT analysis and reconstructions help to determine the spatial orientations of CNC in space and provide useful information in order to anticipate morphological abnormalities of the calcaneus and navicular.

Dynamic repair of scapholunate dissociation with dorsal extensor carpi radialis longus tenodesis

This study investigates the results of a technique using an extensor carpi radialis longus (ECRL) tenodesis for symptomatic scapholunate instability. Symptomatic scapholunate instability has been corrected so far either by limited wrist fusion or by various techniques of soft tissue repair. Limited wrist fusion greatly reduces wrist motion and increases the probability of osteoarthritis in the remaining mobile wrist segments. On the other hand, most types of soft tissue repair are technically difficult to perform and have disappointing results due to the inherent laxity. The presented dynamic approach was used in 20 wrists of 19 patients with static scapholunate instability. Preoperative evaluation included in all patients clinical examination, radiologic evaluation, and arthroscopy for establishing the diagnosis of static scapholunate instability. The technique involves the fixation of the ECRL tendon on the dorsal aspect of the scaphoid by means of a cancellous screw and a special washer. Dynamic ECRL tenodesis of the scaphoid is a safe and simple procedure that enhances the extension forces on the scaphoid in all wrist positions. The results of this preliminary report in 20 wrists showed dynamic ECRL tenodesis to be an effective treatment option for treating symptomatic static scapholunate instability.

Lateral meniscal cyst causing common peroneal palsy

Lateral meniscal cysts are relatively common, but only in rare instances do they cause common peroneal nerve irritation. There are, we believe, no cases reported in which both the sensory and motor functions of the nerve have been compromised. We present a case of a lateral meniscal cyst that became palpable and led to symptoms of numbness and weakness in the distribution of the common peroneal nerve. The MRI findings were of an oblique tear of the lateral meniscus with an associated multiloculated meniscal cyst that coursed behind the biceps tendon before encroaching on the common peroneal nerve. Surgical resection confirmed the tract as located on the MRI and histology confirmed the mass to be a synovial cyst. Resection of the cyst and arthroscopic excision of the meniscal tear led to resolution of the symptoms in 3 months.

Neer Award 2007: Reversion of structural muscle changes caused by chronic rotator cuff tears using continuous musculotendinous traction. An experimental study in sheep

HYPOTHESIS: Chronic rotator cuff tears are associated with irreversible architectural muscle changes and a high rate of repair failure. The changes observed in man and their irreversibility with a single stage repair can be reproduced in sheep. It was the purpose of this experiment to test the hypothesis that slow, continuous elongation of a retracted musculotendinous unit allows reversal of the currently irreversible structural muscle changes. MATERIALS AND METHODS: The infraspinatus tendon of 12 sheep was released using a greater tuberosity osteotomy and allowed to retract for 4 months. Then, a new device was mounted on the scapular spine and used to extend the infraspinatus muscuculotendinous unit transcutaneously by 1 mm per day. Thereafter, the tendon was repaired back to the greater tuberosity. We assessed the muscular architecture using magnetic resonance imaging, macroscopic dissection, histology, and electron microscopy. Fatty infiltration (in Hounsfield units 1/4 HU) and muscular cross-sectional area (in % of the control side) were monitored with computed tomography at tendon release, initiation of elongation, repair, and at sacrifice. RESULTS: Sixteen weeks after tendon release, the mean tendon retraction was 29 +/- 6 mm (14% of original length, P = .008). In 8 sheep, elongation was achieved as planned (group I), but in 4, the elongation failed technically (group II). The mean traction time was 24 +/- 6 days with a mean traction distance of 19 +/- 4 mm. At sacrifice, the mean pennation angle in the infraspinatus of group I was not different from the control side (29.8 degrees +/-7.5 degrees vs. 30 degrees +/-6 degrees , P = .575). In group II, the pennation angle had increased from 30 degrees +/-6 degrees to 55 degrees +/-14 degrees (P = .035). There was no fatty infiltration at the time of tendon release. After retraction, there was a significant increase in fatty infiltration of the infraspinatus muscle and a decrease of its cross-sectional area to 57% of the contralateral side (P = .0001). During traction, the degree of fatty infiltration remained unchanged (36 HU to 38 HU, P = .381), and atrophy improved to a muscle square area of 78% of the contralateral side (P = .0001) in group I. In group II, an increase of fatty infiltration was measured from 36 HU to 28 HU; however, this increase was not significant (P = .144). Atrophy did not change in group II (57-55%, P = .946). At sacrifice, the remaining muscle mass was 64% in group I and 46% in group II (P = .019). DISCUSSION: Our preliminary results document, that continuous elongation of a retracted, fatty infiltrated and atrophied musculotendinous unit is technically feasible. CONCLUSION: In the sheep, continuous elongation can lead to restoration of normal muscle architecture, to partial reversal of muscle atrophy, and to arrest of the progression of fatty infiltration. LEVEL OF EVIDENCE: Basic science level 2; Prospective comparative therapeutic study.

Mechanical signals regulating extracellular matrix gene expression in fibroblasts

Mechanical forces are essential for connective tissue homeostasis. The extracellular matrix (ECM) plays a key role in the transmission of forces generated by the organism (e.g. muscle contraction) and externally applied (e.g. gravity). The expression of specific ECM proteins such as collagens and tenascin-C, as well as of matrix metalloproteinases, involved in their turnover, is influenced by mechanical stimuli. The precise mechanisms by which mechanical strains are translated into chemical signals and lead to differential gene expression are however not fully understood. Cell-matrix adhesion sites are good candidates for hosting a "mechanosensory switch", as they transmit forces from the ECM to the cytoskeleton and vice versa by physically linking the cytoskeleton to the ECM. Integrins, transmembrane proteins located to these adhesion sites, have been shown to trigger a set of internal signaling cascades after mechanical stimulation. We have shown that the expression level of tenascin-C directly correlates with externally applied mechanical stress, as well as with RhoA/RhoA-dependent kinase-mediated cytoskeletal tension. Presumably other genes are regulated in a similar manner. The changes in ECM composition and mechanical properties derived from mechanical stress are relevant in medical intervention after ligament and tendon injury.

Long-term changes in bone metabolism, bone mineral density, quantitative ultrasound parameters, and fracture incidence after spinal cord injury: a cross-sectional observational study in 100 paraplegic men

To study the time course of demineralization and fracture incidence after spinal cord injury (SCI), 100 paraplegic men with complete motor loss were investigated in a cross-sectional study 3 months to 30 years after their traumatic SCI. Fracture history was assessed and verified using patients' files and X-rays. BMD of the lumbar spine (LS), femoral neck (FN), distal forearm (ultradistal part = UDR, 1/3 distal part = 1/3R), distal tibial diaphysis (TDIA), and distal tibial epiphysis (TEPI) was measured using DXA. Stiffness of the calcaneus (QUI.CALC), speed of sound of the tibia (SOS.TIB), and amplitude-dependent SOS across the proximal phalanges (adSOS.PHAL) were measured using QUS. Z-Scores of BMD and quantitative ultrasound (QUS) were plotted against time-since-injury and compared among four groups of paraplegics stratified according to time-since-injury (<1 year, stratum I; 1-9 years, stratum II; 10-19 years, stratum III; 20-29 years, stratum IV). Biochemical markers of bone turnover (deoxypyridinoline/creatinine (D-pyr/Cr), osteocalcin, alkaline phosphatase) and the main parameters of calcium phosphate metabolism were measured. Fifteen out of 98 paraplegics had sustained a total of 39 fragility fractures within 1,010 years of observation. All recorded fractures were fractures of the lower limbs, mean time to first fracture being 8.9 +/- 1.4 years. Fracture incidence increased with time-after-SCI, from 1% in the first 12 months to 4.6%/year in paraplegics since >20 years ( p<.01). The overall fracture incidence was 2.2%/year. Compared with nonfractured paraplegics, those with a fracture history had been injured for a longer time ( p<.01). Furthermore, they had lower Z-scores at FN, TEPI, and TDIA ( p<.01 to <.0001), the largest difference being observed at TDIA, compared with the nonfractured. At the lower limbs, BMD decreased with time at all sites ( r=.49 to.78, all p<.0001). At FN and TEPI, bone loss followed a log curve which leveled off between 1 to 3 years after injury. In contrast, Z-scores of TDIA continuously decreased even beyond 10 years after injury. LS BMD Z-score increased with time-since-SCI ( p<.05). Similarly to DXA, QUS allowed differentiation of early and rapid trabecular bone loss (QUI.CALC) vs slow and continuous cortical bone loss (SOS.TIB). Biochemical markers reflected a disproportion between highly elevated bone resorption and almost normal bone formation early after injury. Turnover declined following a log curve with time-after-SCI, however, D-pyr/Cr remained elevated in 30% of paraplegics injured >10 years. In paraplegic men early (trabecular) and persistent (cortical) bone loss occurs at the lower limbs and leads to an increasing fracture incidence with time-after-SCI.

How well do radiographic absorptiometry and quantitative ultrasound predict osteoporosis at spine or hip? A cost-effectiveness analysis

Dual energy X-ray absorptiometry (DXA) is widely accepted as the reference method for diagnosis and monitoring of osteoporosis and for assessment of fracture risk, especially at hip. However, axial-DXA is not suitable for mass screening, because it is usually confined to specialized centers. We propose a two-step diagnostic approach to postmenopausal osteoporosis: the first step, using an inexpensive, widely available screening technique, aims at risk stratification in postmenopausal women; the second step, DXA of spine and hip is applied only to potentially osteoporotic women preselected on the basis of the screening measurement. In a group of 110 healthy postmenopausal woman, the capability of various peripheral bone measurement techniques to predict osteoporosis at spine and/or hip (T-score < -2.5SD using DXA) was tested using receiver operating characteristic (ROC) curves: radiographic absorptiometry of phalanges (RA), ultrasonometry at calcaneus (QUS. CALC), tibia (SOS.TIB), and phalanges (SOS.PHAL). Thirty-three women had osteoporosis at spine and/or hip with DXA. Areas under the ROC curves were 0.84 for RA, 0.83 for QUS.CALC, 0.77 for SOS.PHAL (p < 0.04 vs RA) and 0.74 for SOS.TIB (p < 0.02 vs RA and p = 0.05 vs QUS.CALC). For levels of sensitivity of 90%, the respective specificities were 67% (RA), 64% (QUS.CALC), 48% (SOS.PHAL), and 39% (SOS.TIB). In a cost-effective two-step, the price of the first step should not exceed 54% (RA), 51% (QUS.CALC), 42% (SOS.PHAL), and 25% (SOS.TIB). In conclusion, RA, QUS.CALC, SOS.PHAL, and SOS.TIB may be useful to preselect postmenopausal women in whom axial DXA is indicated to confirm/exclude osteoporosis at spine or hip.

Graft remodeling during growth following anterior cruciate ligament reconstruction in skeletally immature sheep

INTRODUCTION: Ruptures of the anterior cruciate ligament are being diagnosed with increasing frequency in skeletally immature individuals. It was our aim to investigate the graft remodelling process following an autologous, transphyseal reconstruction of the anterior cruciate ligament (ACL) in skeletally immature sheep. We hypothesized that the ligamentisation process in immature sheep is quicker and more complete when compared to adult sheep. MATERIALS AND METHODS: Skeletally immature sheep with an age of 4 months underwent a fully transphyseal ACL reconstruction using an autologous tendon. The animals were subsequently sacrificed at 3, 6, 12 and 24 weeks following surgery. Each group was characterised histomorphometrically, by immunostaining (VEGF, SMA), by transmission electron microscopy (TEM) and biomechanically (UFS Roboter). RESULTS: The histomorphometric analysis and presence of VEGF and SMA positive cells demonstrated a rapid return to a ligament like structure. The biomechanical analysis revealed an anteroposterior translation that was still increased even 6 months following surgery. CONCLUSION: As in adult sheep models, the remodeling of a soft tissue graft used for ACL reconstruction results in a biomechanically inferior substitute. However, the immature tissue seems to remodel faster and more complete when compared to adults.