Glenoid vault perforation in total shoulder arthroplasty: Do we need computer guidance?

The proliferation of computer 3D simulation and computer-generated guides is aimed at minimizing perforation of the glenoid vault by glenoid pegs in shoulder arthroplasty, based on assumptions that perforation leads to worse outcomes by component loosening and potential failure. We evaluated outcomes of glenoid peg perforation testing the assumption that perforation produces worse results. Eighty-three shoulders underwent shoulder arthroplasty with pegged hybrid fixation (bone-ingrowth flanged central glenoid peg and peripheral cemented pegs) without precision signal injector guides or use of 3D planning software. Outcomes were determined by American Shoulder and Elbow Score and Oxford Shoulder Score. Fine slice CT determined the presence of vault perforation and the extent of lucent lines at the prosthesis-bone interface and bony morphology of the vault perforation. Follow-up was 46.7 months (24-99). Seven shoulders (8%) demonstrated perforation of glenoid vault. Bony ingrowth and cortical overgrowth occurred despite perforation, with no clinically significant differences in clinical or radiological outcomes in shoulders with and without glenoid vault perforation. None of these patients underwent revision surgery. Despite not utilizing computer planning and/or guides, 92% of implants did not perforate the glenoid vault. However, glenoid vault perforation in our series produced excellent outcomes with no increased risk of revision as a result of glenoid vault perforation.

Medium-Term Clinical and Radiographic Results of an All-Polyethylene, Pegged, Bone-Ingrowth Glenoid Component: A Concise Follow-up of a Previous Report.

ABSTRACT: We previously reported the mean 4-year outcomes of anatomic total shoulder replacement using an all-polyethylene, pegged, hybrid-fixation (bone ingrowth and cement) glenoid component. In the present study, we report on that patient cohort after another 4 years of follow-up (mean, 101 months; range, 77 to 146 months). At that time, the median American Shoulder and Elbow Surgeons (ASES) score was 92 points (interquartile range [IQR], 81.7 to 98.3) and the median Oxford Shoulder Score was 47 points (IQR, 41 to 48). Osseointegration, demonstrated by bone ingrowth between the flanges on the central peg as seen on coronal computed tomography (CT), was complete in 75% of the shoulders, partial in 21%, and absent in 4%. There were radiolucent lines at the bone-prosthesis interface on CT, with a median Yian score of 1 (IQR, 0 to 2; range, 0 to 18). The conclusion in the present study was that shoulder arthroplasty with an all-polyethylene, hybrid-fixation (bone ingrowth and cement) pegged glenoid component has durable clinical and radiographic outcomes at medium-term follow-up. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Clinical and Radiographic Results of an All-Polyethylene Pegged Bone-Ingrowth Glenoid Component.

BACKGROUND: Loosening of the glenoid component continues to be the main cause of medium and long-term failure of shoulder replacements. The purpose of this study was to evaluate the early clinical and radiographic results following use of an all-polyethylene pegged glenoid component designed for hybrid (biological and cement) fixation. METHODS: Eighty-three shoulders in 77 patients (mean age, 68.6 years) underwent total shoulder arthroplasty with a pegged hybrid-fixation component (bone-ingrowth glenoid and cemented peg). Outcomes were determined with the American Shoulder and Elbow Surgeons (ASES) score and the Oxford shoulder score. A detailed analysis of radiographs and fine-slice computed tomography (CT) images was performed to determine the extent of bone ingrowth between the flanges and the extent of radiolucent lines at the prosthesis-bone interface. RESULTS: The mean duration of follow-up was 46.7 months (range, 24 to 99 months). At the time of final follow-up, the median ASES score was 97 points (range, 43 to 100 points) and the median Oxford score was 48 points (range, 24 to 48 points). The median active forward elevation was 130° (range, 65° to 170°), median external rotation was 45° (range, 5° to 80°), and median internal rotation was to T11 (range, buttock to T4). Seventy-eight shoulders demonstrated a perfect Lazarus score for radiolucency (0, indicating no radiolucency). Sixty-eight shoulders demonstrated complete osseointegration, with bone ingrowth between all of the flanges seen on coronal CT; 5 demonstrated partial osseointegration; and 10 demonstrated osteolysis around the central peg. Most radiolucent lines were in the inferior Yian zones. There were no correlations between the Yian CT scores and either the ASES or Oxford score (rho = 0.13 and 0.07, respectively). CONCLUSIONS: Total shoulder arthroplasty with an all-polyethylene pegged glenoid component, utilizing hybrid fixation, demonstrated excellent clinical and radiographic results at the time of early follow-up. Radiolucent lines were seen most commonly around the inferior pegs of the prosthesis, and this may represent an incipient mode of failure. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Use of a Bone Graft Drill Harvester to Create the Fenestration During Arthroscopic Ulnohumeral Arthroplasty.

The Outerbridge-Kashiwagi procedure, or ulnohumeral arthroplasty, was described in 1978 as a method of treating elbow arthritis by creating a fenestration in the olecranon fossa. This fenestration diminishes the likelihood of recurrent spurs in the olecranon fossa and coronoid fossa, without loss of structural bony strength. Arthroscopic techniques have now been developed to perform this procedure. We describe an efficient method of creating the fenestration between the olecranon fossa and coronoid fossa during an arthroscopic ulnohumeral arthroplasty, or Outerbridge-Kashiwagi procedure, that also reduces the amount of residual bone debris produced during the resection.

Four-dimensional computed tomography scans facilitate preoperative planning in snapping scapula syndrome.

HYPOTHESIS: Because a 4-dimensional CT scan (4D CT) is able to provide a moving 3-dimensional (3D) image in real time in patients with snapping scapula syndrome, a 4D CT scan should be able to demonstrate bony impingement of the scapula on the posterior thorax. This study was performed to determine if 4D CT scans aid the clinician in defining the size and location of the scapular bone causing impingement in patients with snapping scapula syndrome. MATERIALS AND METHODS: Between October 2009 and August 2013, 12 patients (median age, 26.5 years; range 15-55 years) with snapping scapula syndrome were investigated with 4D CT. The images formed produced a dynamic volume-rendered reconstruction of the scapulothoracic joint that displayed its movements and any dynamic area of impingement of the scapula on surrounding bony structures. Asymmetry between symptomatic and asymptomatic scapulae was used to determine the radiologic cause of the patient's symptoms. After the failure of conservative management, 8 patients underwent surgery for their condition. RESULTS: Five patients demonstrated bony contact of the scapula on the posterior thoracic ribs. Four patients demonstrated no bony contact but close apposition of the scapula to the posterior thoracic ribs. Three patients demonstrated no bony impingement but abnormal movement of the second and third rib caused by a soft-tissue tethering structure. CONCLUSION: The 4D CT scan images defined pathology well in patients with snapping scapula syndrome and improved assessment of the amount and location of the scapular bone and soft tissue causing symptoms.

The danger zone for the plantar and calcaneal divisions of the tibial nerve - a cadaveric study

In this anatomical, cadaveric study we describe a novel method of determining the point of origin of the plantar and calcaneal divisions of the tibial nerve around the tarsal tunnel, in the clinical setting, without requiring the exact path of the nerve to be known. To this end, we describe an area that arises from the midpoint of the navicular-calcaneal line (MP-NCL), which contains both nerve divisions in the majority of cases. We called this area the danger zone. We identified the size and location of this danger zone by dissecting a total of 50 cadaveric feet. We measured the distance from the origin of each nerve division to both the navicular tuberosity and the calcaneal insertion of the Achilles tendon. From these measurements we were able to calculate the distance of each division from the MP-NCL along two axes, the navicular-calcaneal line (NCL) and a line perpendicular to this crossing at the midpoint. The danger zone of the tibial nerve, around the tarsal tunnel is a 16.5 cm² (5.9 x 2.8 cm) quadrilateral area that passes posterior and proximal from the MP-NCL. This area in our study contained both the plantar and calcaneal divisions of the posterior tibial nerve in 82% of cases. Those divisions that arose outside this area (18%) occurred up to 0.5 cm anterior to the MP-NCL and 1.4 cm distal to the NCL

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Synovial chondromatosis affecting a digital proximal interphalangeal joint.

We present a case of synovial chondromatosis affecting the interphalangeal joint where the disease did not clearly manifest itself on pre-operative radiographs. Although rare, surgeons should consider articular synovial chondromatosis as a differential for pain and stiffness in any joint, even those of the hand.

The use of four-dimensional computed tomography to diagnose costoclavicular impingement causing thoracic outlet syndrome.

Thoracic outlet syndrome is caused by compression of the neurovascular structures crossing the interscalene triangle, costoclavicular space or retropectoralis minor space. The costoclavicular space is the most frequent site of arterial compression and is mainly a result of anatomical variations and masses occupying the costoclavicular space causing a compression effect on the vascular or neural structures within it. We present a case of thoracic outlet syndrome caused by dynamic impingement of the clavicle and the second rib diagnosed by four-dimensional computed tomography scanning.

Novel assessment of the sternoclavicular joint with computed tomography for planning interventional approach.

OBJECTIVES: To describe the plane of the sternoclavicular joint (SCJ) to aid planning of instrument orientation during invasive procedures. METHODS: Computed tomography (CT) images of 80 consecutive patients aged 25 to 40 years with appropriate chest imaging series were retrospectively reviewed. Patients with a previous median sternotomy, fused manubriosternal joint or fracture were excluded. The medial clavicle was found to vary greatly in its anatomy such that a representative morphology could not be described. The manubrium was found to be a more consistent structure and was examined in more detail. The angulation of the SCJ was measured in three orthogonal planes using CT multiplanar reformats. Each SCJ (160 in total) was assessed for transverse, coronal, and sagittal angulation of the central manubrial articular surface in respect to the long axis of the manubrial body using a newly devised measurement technique. RESULTS: The mean angles (± standard deviation) of the SCJs were 62.4 ± 9.7° to the transverse plane, 149.3 ± 7.3° to the coronal plane and 69.8 ± 7.5 to the sagittal plane. There was no significant difference in transverse (p = 0.41) or sagittal (p = 0.60) angulation between sides, however there was a significant difference for the coronal plane (p = 0.04). No significant differences were noted between the sexes in any plane. CONCLUSIONS: Increasing use of invasive diagnostic and treatment techniques dictate that a safe approach to the joint should be used to reduce the risk of iatrogenic injury. This study adds to existing knowledge of SCJ anatomy and its variation within the population. Understanding this can minimize the risk to adjacent structures when approaching the SCJ with injection needles or arthroscopic instruments.

Arthroscopic radial head excision in managing elbow trauma.

PURPOSE: This study describes a case series of 15 patients with radial head fractures who underwent radial head excision using an arthroscopic technique. METHODS: Over a four year period, 15 patients (average age 49.6 years) who had sustained a radial head or radial neck fracture underwent an arthroscopic excision of the radial head. Four patients had an unreconstructable comminuted fracture (early group; EG) and 11 patients had pain and loss of motion with an associated non- or malunion (late group; LG). RESULTS: The mean time to surgery following injury was three weeks (one to five) for the EG and 27 weeks (eight-58) for the LG. The average visual analogue scale (VAS) was 1.7 (zero to four), and the average Quick Disabilities of the Arm, Shoulder and Hand (Quick-DASH) score was 24.7 (16-44). At final follow-up, average supination was 62.0° (range 45-75°) and pronation was 63.3° (range 45-75°). There were no complications. CONCLUSION: This series demonstrates that arthroscopic excision of fractures of the radial head and neck is reliable, reproducible and safe, with similar results to open excision. There may also be additional benefits in the short term with regards to speed of healing and rehabilitation.

Conservative management of Dieterich disease: case report.

Dieterich disease is characterized by avascular necrosis of the metacarpal head. The recent literature has described surgical management of this condition relatively soon after its presentation. We present a case treated conservatively with a satisfactory outcome at 28 months.

Evaluation of ultrasound-guided diagnostic local anaesthetic hip joint injection for osteoarthritis.

PURPOSE: The diagnosis of hip osteoarthritis is often complicated by co-existing pathology in the knee and spine, and mismatch between clinical and radiological signs. Temporary pain relief from a local anaesthetic injection into the hip joint has been reported to help localise symptoms, reducing the risk of unnecessary surgery being performed. We hypothesize that good surgical outcome is predicted by good analgesia following diagnostic injection, and that alternative pathology is present when there is no response to injection. METHODS: Data were analysed from a prospective database of 163 consecutive patients who underwent diagnostic hip injection for possible osteoarthritis. We recorded result of injection and whether hip arthroplasty was performed. A good outcome to surgery was defined as subsequent pain relief without significant residual symptoms. RESULTS: A total of 138 patients were suitable for inclusion in the study. Fifty-eight patients had hip arthroplasty following a good response to diagnostic injection. Of these 54 had a good outcome following surgery (93%). There was also a quantitative improvement in pain and function in these patients as measured by 1 year post-operative and pre-operative Harris hip scores (P < 0.0001). A total of 44/49 patients had no surgery following no response to injection. A clear alternative diagnosis to hip osteoarthritis was made in 40 of these patients (91%). CONCLUSION: Diagnostic ultrasound-guided local anaesthetic injection of the hip joint is a useful test in confirming hip pathology. Complete relief of hip pain following intracapsular injection of local anaesthetic is associated with good surgical outcome following joint replacement.

Oxford unicompartmental knee arthroplasty: medial pain and functional outcome in the medium term.

BACKGROUND: In our experience results of the Oxford unicompartmental knee replacement have not been as good as had been expected. A common post operative complaint is of persistent medial knee discomfort, it is not clear why this phenomenon occurs and we have attempted to address this in our study. METHODS: 48 patients were retrospectively identified at a mean of 4.5 years (range = 3 to 6 years) following consecutive Oxford medial Unicompartmental Knee arthroplasties for varus anteromedial osteoarthritis. The mean age at implantation was 67 years (range 57-86). Of these 48 patients, 4 had died, 4 had undergone revision of their unicompartmental knee replacements and 2 had been lost to follow up leaving 38 patients with 40 replaced knees available for analysis using the 'new Oxford Knee Score' questionnaire. During assessment patients were asked specifically whether or not they still experienced medial knee discomfort or pain. RESULTS: The mean 'Oxford score' was only 32.7 (range = 16 to 48) and 22 of the 40 knees were uncomfortable or painful medially.The accuracy of component positioning was recorded, using standard post operative xrays, by summing the angulation or displacement of each component in two planes from the ideal position (according to the 'Oxford knee system radiographic criteria'). No correlation was demonstrated between the radiographic scores and the 'Oxford scores', or with the presence or absence of medial knee discomfort or pain. CONCLUSION: In our hands the functional outcome following Oxford Unicompartmental knee replacement was variable, with a high incidence of medial knee discomfort which did not correlate with the postoperative radiographic scores, pre-op arthritis and positioning of the prosthesis.