Beth P. Smith

Cartilage injuries: A review of 31,516 knee arthroscopies

Although articular cartilage injuries of the knee are common, injured cartilage has a limited ability to heal. Recent data suggest that articular cartilage grafting may provide treatment for these injuries. To define the patient population that might benefit from cartilage grafting, 31,516 knee arthroscopies were reviewed. Between June 1991 and October 1995, 53,569 hyaline cartilage lesions were documented in 19,827 patients. The majority were articular cartilage lesions; grade III lesions of the patella were the most common. Grade IV lesions were predominantly located on the medial femoral condyle. Patients under 40 years of age with grade IV lesions accounted for 5% of all arthroscopies; 74% of these patients had a single chondral lesions (4% of the arthroscopies). No associated ligamentous or meniscal pathology was found in 36.6% of these patients.

Management of cerebral palsy with botulinum-A toxin: preliminary investigation.

Summary: Use of intramuscular botulinum-A toxin (Botox) to produce neuromuscular blockade has been effective in treating certain ocular and facial muscular imbalances as well as spasmodic torticollis. In this preliminary open study, the effectiveness of intramuscularly injected Botox on the muscular imbalances of cerebral palsy was assessed in 27 pediatric patients. Each patient had “dynamic deformities” unresponsive to other treatment, and operation was the only other realistic alternative. The dose of Botox was calculated on a unit/body weight basis. In ambulatory patients, clinical changes in gait were assessed by a physicians rating scale. Reduction in spasticity became apparent in 12–72 h after injection; the effect of Botox after target threshold was reached lasted 3–6 months. No major side effects occurred. Botox may prove a useful adjuvant in conservative management of the spasticity of cerebral palsy. Successful management with these injections may allow delay of surgical intervention until the child is older and at less risk of possible complications, including the need for repeated surgical procedures.

Botulinum Toxin Type A Neuromuscular Blockade in the Treatment of Lower Extremity Spasticity in Cerebral Palsy: A Randomized, Double-Blind, Placebo-Controlled Trial

Increased gastrocnemius/soleus muscle tone in children with cerebral palsy may cause an equinus of the ankle. Botulinum toxin type A (BTX), a neuromuscular blocking agent, reduces muscle tone in various neuromuscular disorders. The safety and short-term efficacy of BTX injections were evaluated in a prospective, 3-month, double-blind, randomized clinical trial involving 114 children with cerebral palsy and dynamic equinus foot deformity. Outcome was determined by observational gait analysis, ankle range-of-motion measurements, and quantification of muscle denervation by nerve conduction. Patients in the BTX group demonstrated improved gait function and partial denervation of the injected muscle. No serious adverse events were reported.

Spasticity associated with cerebral palsy in children: Guidelines for the use of botulinum A toxin

Botulinum A toxin produces selective and reversible chemodenervation that can be employed to balance muscle forces across joints in children with cerebral palsy (CP). Currently, there are two commercially available botulinum A toxin formulations (BOTOX® and Dysport®). The amount of botulinum A toxin required depends upon the number of muscles that are targeted, and the size of the patient. In order to achieve adequate chemodenervation with botulinum A toxin, the following conditions must be met: (i) a sufficient number of units of toxin must be injected in order to neutralize neuromuscular junction (NMJ) activity; (ii) an appropriate drug volume is required in order to optimize the delivery of the toxin to the NMJs; and (iii) localization of the injecting needle through the fascia of the target muscle is necessary. Localization of the injection may be facilitated by active electromyography, ultrasonography, palpation of the muscle belly, and/or use of anatomic landmarks.Botulinum A toxin injections are indicated for use in pediatric patients with CP to: (i) improve motor function by balancing muscle forces across joints; (ii) improve health-related quality of life by decreasing spasticity and/or decreasing caregiver burden; (iii) decrease pain from spasticity; (iv) enhance self-esteem by diminishing inappropriate motor responses; and (v) provide a presurgical diagnostic tool.Following intramuscular injections of botulinum A toxin, short-term benefits of reduced spasticity are observed in approximately 70–82% of children. The intermediate term (1–2 years) efficacy rate is approximately 50%. The most common deformity treated with toxin injections in pediatric patients with CP is equinus foot deformity. However, efficacy of toxin injections for the management of crouched gait, pelvic flexion contracture, cervical spasticity, seating difficulties, and upper extremity deformity also has been documented. In addition, toxin injections have been shown to manage painful muscle spasticity associated with surgery or application of casts and painful cervical spasticity with or without dystonia. Toxin injections can also be used as a diagnostic tool to determine the appropriateness of other interventions by observing the muscle response to the injection in order to gain additional information for the development of a treatment plan. Botulinum A toxin, when used in appropriate doses, is well tolerated.

IntracellularStaphylococcus aureus: A MECHANISM FOR THE INDOLENCE OF OSTEOMYELITIS

Staphylococcus aureus is the bacterial pathogen which is responsible for approximately 80% of all cases of human osteomyelitis. It can invade and remain within osteoblasts. The fate of intracellular Staph. aureus after the death of the osteoblast has not been documented. We exposed human osteoblasts to Staph. aureus. After infection, the osteoblasts were either lysed with Triton X-100 or trypsinised. The bacteria released from both the trypsinised and lysed osteoblasts were cultured and counted. Colonies of the recovered bacteria were then introduced to additional cultures of human osteoblasts. The number of intracellular Staph. aureus recovered from the two techniques was equivalent. Staph. aureus recovered from time zero and 24 hours after infection, followed by lysis/trypsinisation, were capable of invading a second culture of human osteoblasts. Our findings indicate that dead or dying osteoblasts are capable of releasing viable Staph. aureus and that Staph. aureus released from dying or dead osteoblasts is capable of reinfecting human osteoblasts in culture.

Use of a Distraction Plate for Distal Radial Fractures with Metaphyseal and Diaphyseal Comminution

BACKGROUND Distal radial fractures with extensive comminution involving the metaphyseal-diaphyseal junction present a major treatment dilemma. Of particular difficulty are those fractures involving the articular surface. One approach is to apply a dorsal 3.5-mm plate extra-articularly from the radius to the third metacarpal, stabilizing the diaphysis and maintaining distraction across the radiocarpal joint. METHODS Twenty-two patients treated with a distraction plate for a comminuted distal radial fracture were included in the study. With use of three limited incisions, a 3.5-mm ASIF plate was applied in distraction dorsally from the radial diaphysis, bypassing the comminuted segment, to the long-finger metacarpal, where it was fixed distally. The articular surface was anatomically reduced and was secured with Kirschner wires or screws. Eleven of the twenty-two fractures were treated with bone-grafting. The plate was removed after fracture consolidation (at an average of 124 days), and wrist motion was initiated. All patients were followed prospectively with use of radiographs, physical examination, and DASH (Disabilities of the Arm, Shoulder and Hand) scores. RESULTS All fractures united by an average of 110 days. Radiographs showed an average palmar tilt of 4.6 degrees and an average ulnar variance of neutral (0 degrees), whereas loss of radial length averaged 2 mm. Flexion and extension averaged 57 degrees and 65 degrees, respectively, and pronation and supination averaged 77 degrees and 76 degrees , respectively. The average DASH scores were 34 points at six months, 15 points at one year, and 11.5 points at the time of final follow-up (at an average of 24.8 months). According to the Gartland-Werley rating system, fourteen patients had an excellent result, six had a good result, and two had a fair result. Grip strength and the range of motion of the wrist at one year correlated inversely with the proximal extent of fracture comminution into the diaphysis. The duration of plate immobilization did not correlate with the range of motion of the wrist or with the DASH score at one year. CONCLUSIONS The use of a distraction plate combined with reduction of the articular surface and bone-grafting when needed can be an effective technique for treatment of fractures of the distal end of the radius with extensive metaphyseal and diaphyseal comminution. A functional range of motion with minimal disability can be achieved despite a prolonged period of fixation with a distraction plate across the wrist joint.

Robotic systems in orthopaedic surgery

Robots have been used in surgery since the late 1980s. Orthopaedic surgery began to incorporate robotic technology in 1992, with the introduction of ROBODOC, for the planning and performance of total hip replacement. The use of robotic systems has subsequently increased, with promising short-term radiological outcomes when compared with traditional orthopaedic procedures. Robotic systems can be classified into two categories: autonomous and haptic (or surgeon-guided). Passive surgery systems, which represent a third type of technology, have also been adopted recently by orthopaedic surgeons. While autonomous systems have fallen out of favour, tactile systems with technological improvements have become widely used. Specifically, the use of tactile and passive robotic systems in unicompartmental knee replacement (UKR) has addressed some of the historical mechanisms of failure of non-robotic UKR. These systems assist with increasing the accuracy of the alignment of the components and produce more consistent ligament balance. Short-term improvements in clinical and radiological outcomes have increased the popularity of robot-assisted UKR. Robot-assisted orthopaedic surgery has the potential for improving surgical outcomes. We discuss the different types of robotic systems available for use in orthopaedics and consider the indication, contraindications and limitations of these technologies.

The microcirculatory effects of peripheral sympathectomy

Microvascular physiology following peripheral artery sympathectomy was evaluated in seven hands with refractory pain (n = 7) and ulceration (n = 7) by serial isolated cold stress testing, which measures digital temperature and cutaneous perfusion (laser Doppler fluxmetry). All patients (n = 6) had vasospasm (secondary Raynauds phenomenon) and arteriographically proven digital and palmar occlusive disease. Microcirculatory flow responses were correlated with symptoms and signs (including ulcer healing) before and after (2-8 weeks, 12-15 weeks, and 24 weeks) peripheral sympathectomy. Baseline data were compared with those of controls (n = 7 extremities). Following surgery, all seven hands had diminished pain; six had ulcer healing and one had ulcer reduction. Isolated cold stress testing demonstrated abnormalities in temperature and laser Doppler fluxmetry response between patients and controls. Although total flow (reflected by temperature) was not significantly increased after surgery, peripheral sympathectomy increased nutritional flow in these patients with combined vasospastic vessels and occlusive injury. The clinical changes observed following peripheral sympathectomy appear to be related to postsurgical correction of abnormal arteriovenous shunting and to improved nutritional blood flow to ischemic areas. This accounts for the resultant diminution of pain and healing of ulcers observed in these patients after surgery.

Severe contractures of the proximal interphalangeal joint in Dupuytren's disease : results of a prospective trial of operative correction and dynamic extension splinting

In a prospective study, 23 proximal interphalangeal joints that were severely contracted (> or = 45 degrees) as a result of Dupuytrens disease underwent operative correction and 6 months of dynamic extension splinting. Proximal interphalangeal joint extension was measured preoperatively and postoperatively at 3-month intervals for 1 year and at 6-month intervals thereafter. Mean follow-up was 2 years (minimum, 1 year). Overall, at 2 years, 44% improvement in proximal interphalangeal joint extension was noted. Mean improvement of 59% in proximal interphalangeal joint extension was noted in patients who complied with the postoperative dynamic extension splinting program. Patients who were noncomplaint demonstrated a 25% improvement in proximal interphalangeal joint extension. The difference in values between patients who were compliant and those who were not was statistically significant. Other factors--severity of contracture, digit involved, and the necessity for capsular release--were not significantly related to outcome. This study suggests that soft tissue responds to continuous dynamic extension stresses and can be remodeled over time.

Stimulation of cholesterol esterification in rhesus monkey arterial smooth muscle cells.

SUMMARY The influence of homologous high density lipoprotein (HDL) and low density lipoprotein (LDL) and of whole hypercholesterolemic serum on the esterification of oleic acid and cholesterol was studied in rhesus monkey arterial smooth muscle cells. Whole hypercholesterolemic serum and isolated LDL stimulated cholesterol esterification as much as 10-fold using either cholesterol-1,2-3H or oleate-l-14C as substrate. At the same concentrations of cholesterol, HDL stimulated cholesterol esterification to a lesser extent, to a maximum of 3-fold. Associated with the stimulation of cholesterol esterification by LDL or whole hypercholesterolemic serum was a greater than 10-fold increase in the cholesteryl ester content of the arterial smooth muscle cells. Esterification to cholesterol reached a maximum after 8–12 hours of culture with either hypercholesterolemic serum or LDL. The stimulation of esterification was specific for esterification to cholesterol because there was little change in incorporation of fatty acid into triglycerides and phospholipids. These studies provide further evidence that a major consequence of the interaction of plasma LDL with the cellular elements of the arterial wall is a stimulation of cholesterol esterification. These studies, coupled with the observation that cholesteryl esters, more than any other single component, increase in the atherosclerotic artery, suggest an important role of a stimulation in cholesterol esterification in the pathogenesis of atherosclerosis.