Cells of the intervertebral disc exist in an unusual environment compared to those of other tissues. Within the disc there are low levels of nutrients available, low oxygen levels and it is an acidic environment due to high lactate levels. Apoptosis (programmed or controlled cell death) has been reported in intervertebral discs, as well as necrosis (uncontrolled cell death). This study has focused on examining the sensitivity of nucleus pulpo-sus (NP) cells to several stimuli, in comparison to two other cells types. Ultra violet (UV) irradiation, serum starvation (with no foetal calf serum) and treatment with 2mM hydrogen peroxide were used to induce apoptosis in cultured bovine NP cells, HeLa (cancer cell line) and 293T cells (human embryo kidney derived) cells. Apoptosis was identified by nuclear morphology following staining with fluorescent Hoechst 33342 dye and propidium iodide; the incidence was measured at 24, 48 and 72 hours. Untreated controls were used for each treatment and at each time point. The incidence of apoptosis increased with time for all treatments. After 72 hours, UV treatment produced the highest levels of apoptosis with levels of apoptosis occurring in the order of HeLa (94%) >
NP cells (29%) >
293T cells (15%). Treatment with hydrogen peroxide and serum starvation induced apoptosis at lower levels in all three cell types (maximum of 30%). Serum starvation induced apoptosis in only 10% of NP cells at 72 hours, compared to 20% in HeLa cells. None of the controls contained apoptotic cells. NP cells are stimulated to apoptose in response to UV irradiation, hydrogen peroxide and serum starvation. However, levels of apoptosis are much lower after UV treatment in comparison to HeLa cells (3 times lower), suggesting that they may have a protective mechanism to this apoptotic stimulus, compared to HeLa cells. The low levels of apoptosis observed in NP cells with serum starvation may be due to the low nutrient environment that they exist in normally.
Panton-Valentine leukocidin secreted by The Panton-Valentine leukocidin toxin not only destroys host neutrophils, immunocompromising the patient, but also increases the risk of intravascular coagulopathy. This combination leads to widespread involvement of bone with glutinous pus which is difficult to drain, and makes the delivery of antibiotics and eradication of infection very difficult without surgical intervention.
Introduction Pathophysiology of glenohumeral arthritis differs depending upon type of arthritis Osteoarthritis Post-traumatic arthritis Inflammatory arthritis (i.e. RA) Arthritis of instability Crystalline arthritis (Milwaukee shoulder, cuff tear arthropathy) Avascular necrosis Natural history as well as response to treatment are both pathology dependent Soft-tissue involvement Rotator cuff tear Soft tissue contracture Secondary osseous deformity Regional osteopenia Glenoid wear (concentric versus eccentric) Humeral collapse Surgical options Joint-sparing techniques Arthroscopic capsular release/ joint debridement/synovectomy Open debridement, subscapularis lengthening Open capsular interposition Osteotomy Glenoid Humeral Cartilage transplantation Arthrodesis Resection arthroplasty Joint replacement Unconstrained Hemiarthroplasty Total shoulder replacement Constrained Joint-sparing Techniques These techniques are only useful in patients with early changes or who are too young and active for joint replacement Arthroscopic debridement or capsular release Young patients Normal joint alignment Severe asymmetric capsular contracture (i.e. arthritis of instability) Open debridement Large humeral osteophytes Subscapularis lengthening Open capsular interposition Lateral edge of anterior capsule sutured to posterior labrum Less severe degrees of contracture, subscapularis must be repaired anatomically Osteotomy Only useful in situations where there is abnormal humeral or glenoid alignment Glenoid – posterior opening wedge for osteoarthritis in combination with posterior glenoid hypoplasia or increased retroversion Humeral – most useful for post-fracture deformity (i.e. varus of the surgical neck) Cartilage Transplantation Very early experience and really only attempted in any numbers in the knee Chondrocyte transplantation very expensive and tedious Currently, the most popular techniques involve transplanting plugs or cores of articular cartilage, subchondral bone, and cancellous bone Autograft- harvest from non-weight-bearing or less weight-bearing area the same or different bone Lateral femoral condyle Posterolateral humeral head Allograft Early attempts limited by chondrocyte viability after harvest Improved processing techniques have recently improved chondrocyte survival to 60–70% Offers the desirable option of being able to preoperatively match radii of curvature of implant to donor site Arthrodesis Fortunately, rarely indicated. Patients miss the ability to rotate the humerus Indications Brachial plexus injury Combined deltoid and rotator cuff deficiency Young heavy labourer Sepsis Severe bone loss Requires functional trapezius and serratus anterior Resectional Arthroplasty (Jones Procedure) Even more rarely indicated than arthrodesis Function is better if rotator cuff is attached to proximal humerus Indications Sepsis Failed arthroplasty Combined deltoid and rotator cuff deficiency Conclusions Hemiarthroplasty or total shoulder replacement with unconstrained implants is the surgical treatment of choice in the vast majority of patients with glenohumeral arthritis Joint-sparing procedures are indicated in young patients with early, less extensive changes Arthrodesis and resection arthroplasty are rarely indicated, except under unusual circumstances of soft-tissue deficiency, nerve injury, or sepsis Cartilage transplantation shows promise in very select patients
Introduction Definition-in this presentation, the discussion will not include reparable cuff deficiency, as this is handled with standard arthroplasty techniques combined with cuff repair Factors that affect decision-making Kinematics-fixed fulcrum or not Bone loss Deltoid integrity Coracoacromial arch integrity Age Activity level Options Hemiarthroplasty “ Extended head” hemiarthroplasty Arthroplasty + tendon transfer Constrained arthroplasty – currently not FDA approved in USA Arthrodesis Evaluation History and physical examination ? Prior surgery ? Overhead function – does fixed-fulcrum kinematics exist even if the head is not centred ? Anterosuperior instability – lack of fixedfulcrum kinematics Cuff strength Deltoid integrity Radiographs – bone loss, especially glenoid Other imaging studies not necessary Arthroplasty Hemiarthroplasty Best if fixed fulcrum kinematics exists – intact CA arch, intact deltoid, at or above shoulder elevation Technical considerations Preserve deltoid Preserve coracoacromial ligament, acromion ? Preserve remaining subscapularis – make humeral cut superiorly, through the rotator cuff defect Alternatively, take down subscapularis and capsule in one layer, mobilise and repair or transpose superiorly Increase retroversion of humeral cut- be careful of posterior cuff (teres minor) attachment Glenoid deficiency – especially if anterior or anterosuperior instability is present. May need to graft glenoid with head. Humeral head size-the same size or slightly larger than the one removed; avoid overstuffing “Extended head” hemiarthroplasty (CTA head) Indications same as hemiarthroplasty Advantages Provides resurfacing of greater tuberosity, which is articulating with the acromion and often irregular Potentially improves kinematics by providing a “pain free” fulcrum Technical considerations Difficult but not impossible to do through a superior, subscapularis sparing approach Special jig required for cutting tuberosity Preserve CA arch Preserve deltoid Increase retroversion (be careful of remaining posterior cuff attachment) Glenoid deficiency – especially if anterior or anterosuperior instability is present. May need to graft glenoid with head. Humeral head size-the same size or slightly larger than the one removed; avoid overstuffing Hemiarthroplasty + tendon transfer Indications Complete subscapularis deficiency Posterior cuff insufficiency with anterosuperior subluxation or dislocation Techniques Latissimus transfer – posterior cuff insufficiency Pectoralis major transfer – subscapularis insufficiency Deep to conjoined tendon (Resch) Superficial to conjoined tendon (Rockwood and Wirth) Combined Constrained arthroplasty Not FDA approved in US Delta III – reverse prosthesis Reasonable results with medium-term follow-up in Europe (5–10 years) Rehabilitation Limited goals Primary goals are pain relief and stability Passive flexion to 90°, passive ER to 30° for 4 weeks Advance stretches and add active range of motion and active assisted range of motion (overhead pulley) at 4 weeks Strengthening – 6 weeks Results Less predictable and less functional overall than most other disease categories (e.g., OA) Average elevation in most series is 120° Usually good pain relief except in patients with anterosuperior subluxation
Introduction The most difficult part of shoulder replacement Important steps Anaesthesia and patient position Soft-tissue releases Humeral bone removal Retractor placement Anaesthesia and Patient Position Need full paralysis Patient must be positioned laterally enough so that the scapula is unsupported Arm is draped free so that it can be manoeuvred to find the position of optimal glenoid visualisation – usually this is slight extension, external rotation, and GH elevation to 45 – 60° Soft-tissue Releases Humeral side – make sure that the rotator interval is incised all the way to the glenoid margin and that the inferior capsule is released past the six o’clock position Glenoid Circumferential labral excision Circumferential capsular release Check for biceps glide Humeral Bone Removal Remove all osteophytes – inferior, anterior, and posterior Make sure humeral osteotomy is through anatomic neck so that there is minimal bone protruding beyond the humeral cuff reflection Retractor Placement Retractors needed Ring retractor (e.g., Fukuda) – both small and large Other types of humeral head retractors (e.g., Carter Rowe) Reverse Homan x2 Single prong Bankart retractor Large flat retractor (e.g., Darrach) Placement Fukuda or Carter Rowe retractor – within the joint, levering on the posterior glenoid to displace humeral head posteriorly Large Darrach – on anterior neck of scapula retracting subscapularis Single prong Bankart or reverse Homan – superior glenoid under biceps anchor Reverse Homan – inferior glenoid. Not always necessary.
1. A course of treatment is suggested for patients with stove-in chests based on experience with seven patients, only one of whom died from his injury. 2. The literature on this subject is reviewed and it is suggested that treatment may be undertaken by an accident surgeon without recourse to intermittent positive pressure respiration inmost instances.
1. Fifteen cases of bone transplantation for fibrous union of fractures of long bones are described, using boiled minced cancellous bone from cadavers. One transplant became infected but the infection responded to treatment. 2. In one patient with non-union of the shaft of the humerus, bony union was not obtained, but a good functional result obviated further treatment. 3. It is suggested that this relatively simple method of bone transplantation could be used more widely if its potentialities were appreciated more fully.
