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Biomedical subjects

David Ring

Publications and source records attributed to David Ring.

At least 55 records · Page 3Linked to original sources
PubMed2004

Treatment of osteoporotic distal radius fractures.

Fracture of distal radius is most commonly an injury of the fit osteoporotic patient. As the population and health of older individuals continue to expand, osteoporotic distal radius fractures will become increasingly common. While many older patients have limited functional demands and can accept some deformity and wrist dysfunction, others remain very active into older age and desire optimal wrist alignment and function. The difficulty obtaining reliable fixation in osteoporotic bone presents a challenge to the surgeon that has been partially addressed by newer implants with screws that directly engage the plate, creating fixed angle bolts that have better fixation in osteoporotic bone. Decision-making is based upon a balance of the goals of the individual patient with the risks of intervention.

Aged↗
PubMed2004

Open reduction and internal fixation of fractures of the radial head.

Early reports of open reduction and internal fixation of fractures of the radial head were positive, perhaps because of the prevalence of isolated partial head fractures for which good results would be expected. Subsequent reports have found that complex fractures of the radial head are prone to early failure, nonunion, and poor forearm rotation after operative fixation. Combined with increased availability and use of metal radial head prosthesis for complex fractures of the radial head, the role of open reduction and inter-nal fixation is being redefined.

Epiphyses↗
PubMed2004

Radial nerve palsy associated with high-energy humeral shaft fractures.

PURPOSE: To determine whether the radial nerve should be explored when there is a complete sensory and motor deficit after a high-energy fracture of the humeral diaphysis. METHODS: Twenty-four patients aged 16 years or older with a high-energy, diaphyseal fracture of the humerus and complete motor and sensory radial nerve palsy were reviewed retrospectively. Eleven fractures were open-6 of these were part of a very complex upper-extremity injury (multiple ipsilateral fractures in 3 patients and near amputation in 3). All 11 patients with open fractures and 3 of 13 patients with closed injuries had radial nerve exploration. RESULTS: All 6 patients with a transected radial nerve had an open humerus fracture and were part of a complex upper-extremity injury. Five of 6 had primary repair of the radial nerve, and none recovered. All 8 intact explored nerves and 9 of 10 unexplored nerves recovered; the only nonrecovery occurred in a patient treated with closed intramedullary rod fixation who may have had iatrogenic nerve injury. The average time to initial signs of recovery was 7 weeks (range, 1-25 weeks). The average time to full recovery was 6 months (range, 1-21 months). CONCLUSIONS: Transection of the radial nerve is usually associated with open fractures of the humerus that are part of a very complex upper-extremity injury. The results of primary nerve repair in this circumstance are poor, likely related to an extensive zone of injury and the need for nerve grafting. Intact nerves and nerve palsies that are part of a closed fracture nearly always recover, even after high-energy injuries. Because the first signs of nerve recovery and complete recovery of the nerve can be quite delayed, patience is merited before considering tendon transfers.

Adolescent↗
PubMed2004

Condylar blade plate fixation of unstable fractures of the distal ulna associated with fracture of the distal radius.

PURPOSE: To review the results of condylar blade plate fixation of unstable fractures of the distal ulna associated with fracture of the distal radius. METHODS: Twenty-four patients in whom a minicondylar blade plate was used to repair an unstable fracture of the distal ulna associated with a fracture of the distal radius were reviewed retrospectively an average of 26 months (range, 12-50 months) after injury. According to the Q modifier of the Comprehensive Classification of Fractures, there were 1 simple fracture of the ulnar neck (Q2), 20 comminuted fractures of the ulnar neck (Q3), and 3 fractures of the head and neck (Q5). Subsequent surgeries included repeat fixation and autogenous cancellous bone grafting in 2 patients with nonunion of the distal radius and 1 with nonunion of the distal ulna. Seven patients had a second operation to remove the ulnar plate secondary to discomfort from plate prominence. RESULTS: The final average motion was as follows: degrees of flexion (range, 30 degrees-80 degrees), 52 degrees of extension (range, 40 degrees-90 degrees), 76 degrees of pronation (range, 45 degrees-90 degrees), and 70 degrees of supination (range, 45 degrees-90 degrees). Grip strength averaged 64% of the contralateral, uninjured extremity (range, 35%-100%). Final radiographic measurements included an average palmar tilt of the distal articular surface of the radius of 8 degrees (range, 0 degrees-20 degrees of palmar tilt), ulnar inclination of 21 degrees (range, 15 degrees-25 degrees), and ulnar positive variance of 1 mm (range, 0-4 mm). There were no problems related to the distal radioulnar joint. According to the system of Gartland and Werley as modified by Sarmiento, there were 6 excellent, 15 good, and 4 fair results at final evaluation. CONCLUSION: For unstable fractures of the distal ulna associated with fracture of the distal radius, condylar blade plate fixation can achieve healing with good alignment, satisfactory function, and an acceptable rate of secondary surgery.

Adolescent↗
PubMed2004

Volar Barton's fractures with concomitant dorsal fracture in older patients.

PURPOSE: To describe a variant of Barton's volar articular shearing fracture of the distal radial articular surface with a subtle concomitant fracture of the dorsal metaphyseal cortex. METHODS: This fracture pattern was observed in 6 women and 2 men with an average age of 67 years (range, 58-76 years). All 8 patients were treated with a volar plate and screws. The dorsal metaphyseal fracture was not recognized in 5 patients and a volar buttress plating technique using an intentionally undercontoured volar plate was used. In 3 patients the dorsal fracture line was identified before surgery and the plate was contoured to fit the volar surface of the distal radius. RESULTS: All 5 patients treated with an undercontoured plate had loss of the normal palmar tilt of the distal radius (average,-9.4 degrees; range, 0 degrees to-22 degrees ) and dorsal translation of the distal radial articular fragments. For the entire group the palmar tilt averaged-5.9 degrees (range, 0.0 degrees to-22.0 degrees ), the ulnar inclination 19 degrees (range, 10 degrees -23 degrees ), and the ulnar variance-0.9 mm (range, 0.0 to-3.0 mm). All patients attained forearm supination of 80 degrees and the average pronation was 75 degrees (range, 45 degrees -80 degrees ). According to Sarmiento's modification of the system of Gartland and Werley there were 1 excellent, 6 good, and 1 fair results. The average Patient-Rated Wrist Evaluation score was 16 (range, 0-35). CONCLUSIONS: Some fractures with an oblique volar marginal articular fracture of the distal radius and volar radiocarpal subluxation (known as Barton's fracture) may also have a fracture through the dorsal metaphyseal cortex. Failure to identify this fracture line can lead to dorsal translation and angulation of the distal radius articular surface, particularly when an undercontoured volar plate is used for internal fixation.

Aged↗
PubMed2004

Surgical treatment of persistent dislocation or subluxation of the ulnohumeral joint after fracture-dislocation of the elbow.

PURPOSE: To review the results of surgical reconstruction of posttraumatic elbow instability in the setting of either intact or repaired olecranon process using a protocol incorporating hinged elbow fixation. METHODS: Thirteen consecutive patients with ulnohumeral instability after a fracture-dislocation of the elbow, adequate articular surfaces, and adequate, stable alignment of the olecranon were treated with temporary hinged external fixation, preservation, or reconstruction of both the coronoid process and radiocapitellar contact and with repair or reconstruction of the lateral collateral ligament complex. There were 9 men and 4 women with an average age of 45 years. Seven patients had a terrible triad pattern injury and 6 had a posterior Monteggia pattern injury. All 13 patients had fracture of the radial head and 10 patients had fracture of the coronoid process. RESULTS: At an average follow-up period of 57 months stability was restored in every patient. The average Disabilities of the Arm, Shoulder, and Hand questionnaire score was 15 and the average Mayo score was 84, with 6 excellent, 4 good, and 3 fair results. The average arc of ulnohumeral motion was 99 degrees. Six patients had radiographic signs of arthrosis including 5 of 6 patients with olecranon fracture-dislocations. CONCLUSIONS: A stable, functional elbow can be restored in most patients with persistent instability after fracture-dislocation of the elbow using a treatment protocol incorporating hinged external fixation.

Adult↗
PubMed2004

Loss of alignment after surgical treatment of posterior Monteggia fractures: salvage with dorsal contoured plating.

PURPOSE: To review the results of internal fixation with a dorsal contoured plate in patients with malalignment after internal fixation of a posterior Monteggia fracture. METHODS: Seventeen patients with malalignment after surgical treatment of a posterior Monteggia fracture were treated with realignment of the ulna and fixation with a contoured dorsal plate. Fifteen patients had loose fixation and 12 patients had subluxation or dislocation of the ulnohumeral joint. Sixteen patients had fracture of the radial head and 9 patients had fracture of the coronoid process. Nine patients had ancillary procedures on the radial head, 4 had ancillary procedures on the coronoid, 5 had hinged external fixation, and one had fascial arthroplasty. Seven patients had another surgery before the final evaluation related to a complication in 6 patients and a to subsequent injury in 1 patient. RESULTS: At the final evaluation at an average of 59 months the fracture was healed and the ulnohumeral joint was reduced concentrically in all 17 patients. The average arc of elbow flexion was 108 degrees and the average arc of forearm rotation was 134 degrees. The average American Shoulder and Elbow Surgeons Elbow Evaluation Score was 88. According to the system of Broberg and Morrey, the final result was rated excellent for 5 patients, good for 9, fair for 2, and poor for 1. One patient had fascial arthroplasty as part of the index procedure and 9 patients had radiographic signs of ulnohumeral arthrosis. CONCLUSIONS: Malalignment after surgical treatment of posterior Monteggia fractures often is associated with unstable fixation. Dorsal contoured plating of the ulna in combination with other procedures can help salvage a malaligned posterior Monteggia fracture with satisfactory function restored in the majority of patients.

Adult↗
PubMed2004

Olecranon osteotomy for exposure of fractures and nonunions of the distal humerus.

Although olecranon osteotomy provides excellent exposure of the distal humerus, enthusiasm for this approach has been limited by reports suggesting numerous complications. It has been suggested that specific techniques for creating and repairing an olecranon osteotomy may help limit complications. This paper describes a technique for olecranon osteotomy using an apex, distal, chevron-shaped osteotomy, Kirschner wires directed out the anterior ulnar cortex distal to the coronoid process and bent 180degrees and impacted into the olecranon proximally, and two 22- gauge, figure-of-eight, stainless steel tension wires. A single surgeon used this technique for exposure of a fracture (16 patients) or nonunion (29 patients) of the distal humerus in 45 consecutive patients. One patient returned to activity too soon, had loosening of the wire fixation, and required a second operation for plate fixation of the ulna. The remaining 44 osteotomies (98%) healed with good alignment within 6 months. There were no broken or migrated wires prior to healing. Twelve patients (27%) had removal of the wires used to repair the olecranon: in 6 patients, this was for symptoms related to the wires (13%); 1 for septic olecranon bursitis, and 5 at the time of another procedure (elbow capsular release in 4 patients and submuscular ulnar nerve transposition in 1). Olecranon osteotomy can be used for exposure of the distal humerus with a low rate of complications when specific techniques are used.

Adolescent↗
PubMed2004

Excision of heterotopic bone around the elbow.

Heterotopic ossification about the elbow is common and sometimes contributes to a disabling loss of motion. The traditional trepidation and pessimism regarding surgical excision of heterotopic bone is giving way to a realization that operative treatment is successful in most cases and dramatic functional improvements can be obtained. Familiarity with extensile exposure and operative technique will increase the safety and efficacy of the procedure.

Journal Article↗
PubMed2004

Locking compression plates for osteoporotic nonunions of the diaphyseal humerus.

Poor bone quality increases the technical difficulty and complications of operative treatment of nonunions and delayed unions of the diaphyseal humerus in older patients. Plates with screws that lock to the plate (transforming each screw into a fixed blade) are intended to improve the fixation of poor quality bone. Twenty-four patients (20 women, four men) with an average age of 72 years (range, 52-86 years) were followed up for a minimum of 12 months after locking compression plate fixation of an osteopenic delayed union (nine patients) or nonunion (15 patients) of the diaphyseal humerus. Twelve patients had iliac crest cancellous bone grafts, two patients had local graft, and 13 patients had demineralized bone applied to the fracture site. All the fractures eventually healed; two healed after a second procedure for autogenous bone grafting in patients who initially received demineralized bone. Using a modification of the Constant and Murley shoulder score, the results were good or excellent in 22 patients, and fair in two patients. Locking compression plates provide stable fixation of poor quality bone in patients with delayed union or nonunion of the humerus. Successful union and restoration of function are achieved in most patients. We no longer consider osteoporosis a contraindication to operative fixation of an ununited fracture of the humeral diaphysis.

Aged↗
PubMed2004

Effective treatment of fracture-dislocations of the olecranon requires a stable trochlear notch.

Our goal with this study was to better define and characterize fracture-dislocations of the olecranon and to provide additional data regarding complications and elbow function after operative treatment. Twenty-six patients with fracture-dislocations of the elbow were reviewed retrospectively. Ten had anterior and 16 had posterior fracture-dislocations. Five of 10 patients with anterior injuries and all of the patients with posterior injuries had an associated fracture of the coronoid process of the ulna. One of 10 patients with anterior and 13 of 16 patients with posterior injuries had fracture of the radial head. Only one patient had a true dislocation of the ulnohumeral joint. In the other 25 patients the articular surfaces remained apposed. All 26 patients were treated operatively and followed up for at least 3 years (average, 6 years). The results were good or excellent in 21 of 26 patients according to the system of Broberg and Morrey. The five unsatisfactory results were related to inadequate fixation of the coronoid with subsequent arthrosis (three patients), proximal radioulnar synostosis (three patients), and a subsequent fracture of the distal humerus (one patient). Fracture-dislocations of the olecranon occur in anterior and posterior patterns with specific injury characteristics and pitfalls. The key to effective treatment is stable restoration of the trochlear notch.

Adult↗
PubMed2004

Operative release of ankylosis of the elbow due to heterotopic ossification. Surgical technique.

BACKGROUND: Although uncommon, complete ankylosis of the elbow secondary to heterotopic ossification results in severe disability. The results of surgical management remain unclear. METHODS: A single surgeon used a consistent operative technique to treat complete osseous ankylosis of the elbow in eleven limbs in seven patients after severe burns and in nine elbows in eight patients after trauma. The elbows in the burn cohort were more often ankylosed in extension (average, 47 degrees of flexion) compared with those in the trauma cohort (66 degrees of flexion), and they had more skin problems (three elbows required a free microvascular muscle transfer for coverage) and associated problems of the shoulder, wrist, and hand. RESULTS: Four patients in the burn cohort and three patients in the trauma cohort failed to regain at least 80 degrees of ulnohumeral motion. After a repeat release in three burn patients and three trauma patients, and at an average follow-up of forty months, the average arc of ulnohumeral motion was 81 degrees in the burn cohort and 94 degrees in the trauma cohort. Six of the eleven limbs in the burn cohort and five of the nine in the trauma cohort had a good result. The average score according to the American Shoulder and Elbow Surgeons elbow assessment form was 72 points for the burn cohort and 76 points for the trauma cohort. CONCLUSIONS: Osseous ankylosis of the elbow is a severely disabling problem, and attempts to regain mobility are both worthwhile and safe. The results are comparable when the ankylosis is caused by burns or trauma despite the greater complexity of osseous ankylosis in the burned arm. Patients and surgeons should be aware of the small risk of recurrent heterotopic ossification and the moderate risk of pain or recurrent contracture after operative release.

Ankylosis↗
PubMed2004

Idiopathic arm pain.

BACKGROUND: Arm pain with little or no objective abnormality (referred to herein as idiopathic arm pain) is a common and frustrating problem for both patients and physicians. We investigated the relative effect of idiopathic arm pain and arm pain due to a discrete diagnosis on upper-extremity-specific health status. METHODS: The Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire was completed by 3888 patients seen over a twelve-month period. Scores for the entire sample, for 496 patients diagnosed with idiopathic arm pain, and for 1379 patients diagnosed with one of twenty-one discrete conditions were compared. RESULTS: Patients with idiopathic pain reported substantial and highly variable upper-limb-specific dysfunction (average DASH score [and standard deviation], 36 +/- 24 points). Patients with discrete diagnoses also exhibited substantial variation (average standard deviation, 25; range, 6 to 27) as well as long right tails indicating floor effects, particularly for less severe conditions (Pearson correlation of r = -0.87 between the mean DASH score and skewness). Analysis of variance confirmed the ability of the DASH instrument to discriminate among groups of diagnoses of varying severity, but post hoc Tukey analysis identified ten subgroups with substantial overlap of the DASH scores. CONCLUSIONS: Patients with idiopathic arm pain report substantial and highly variable upper-extremity dysfunction. The wide variations observed in the DASH scores of the patients with idiopathic pain and those with discrete diagnoses are greater than would be expected on the basis of the variations in the objective pathological conditions and may reflect the strong influence of psychological and sociological factors on health status measures.

Arm↗
PubMed2004

Combined dorsal and volar plate fixation of complex fractures of the distal part of the radius.

BACKGROUND: Fractures of the distal part of the radius that are associated with complex comminution of both the articular surface and the metaphysis (subgroup C3.2 according to the Comprehensive Classification of Fractures) are a challenge for surgeons using standard operative techniques. METHODS: Twenty-five patients with subgroup-C3.2 fractures that had been treated with combined dorsal and volar plate fixation were evaluated at an average of twenty-six months after the injury. Subsequent procedures included implant removal in twenty-one patients and reconstruction of a ruptured tendon in two patients. RESULTS: An average of 54 degrees of extension, 51 degrees of flexion, 79 degrees of pronation, and 74 degrees of supination were achieved. The grip strength in the involved limb was an average of 78% of that in the contralateral limb. The average radiographic measurements were 2 degrees of dorsal angulation, 21 degrees of ulnar inclination, 0.8 mm of positive ulnar variance, and 0.7 mm of articular incongruity. Seven patients had radiographic signs of arthrosis during the follow-up period. A good or excellent functional result was achieved for twenty-four patients (96%) according to the rating system of Gartland and Werley and for ten patients (40%) according to the more stringent modified system of Green and O'Brien. CONCLUSIONS: Combined dorsal and volar plate fixation of the distal part of the radius can achieve a stable, mobile wrist in patients with very complex fractures. The results are limited by the severity of the injury and may deteriorate with longer follow-up. A second operation for implant removal is common, and there is a small risk of tendon-related complications.

Adult↗
PubMed2004

Ununited diaphyseal forearm fractures with segmental defects: plate fixation and autogenous cancellous bone-grafting.

BACKGROUND: With current techniques of plate-and-screw fixation, diaphyseal nonunions of the radius and ulna are unusual. The few reports that have been published have discussed the use of structural corticocancellous bone grafts for the treatment of atrophic nonunions that are associated with osseous defects. We reviewed the rate of union and the functional results in association with the use of plate-and-screw fixation and autogenous cancellous (nonstructural) bone grafts. METHODS: Thirty-five patients with an atrophic ununited diaphyseal fracture of the forearm were treated with 3.5-mm plate-and-screw fixation and autogenous cancellous bone-grafting. A segmental osseous defect with an average size of 2.2 cm (range, 1 to 6 cm) was present in each patient. Twenty of the original fractures had been open. Eleven patients had had treatment of a deep infection before referral to us. The nonunion involved both forearm bones in eight patients, the radius alone in sixteen patients, and the ulna alone in eleven patients. RESULTS: The atrophic nonunion was associated with an open fracture in twenty patients, suboptimal fixation in twenty-two, a fracture-dislocation of the forearm in nine, and infection in eleven. All fractures healed without additional intervention within six months. Two patients had a subsequent Darrach resection of the distal part of the ulna for the treatment of arthrosis of the distal radioulnar joint. After an average duration of follow-up of forty-three months, the final arc of motion averaged 121 degrees in the forearm, 131 degrees at the elbow, and 137 degrees at the wrist, with an average grip strength of 83% compared with that of the contralateral limb. According to the system of Anderson and colleagues, five patients had an excellent result, eighteen had a satisfactory result, eleven had an unsatisfactory result (because of elbow stiffness related to associated elbow injuries in three and because of wrist stiffness in eight), and one had a poor result (because of malunion). CONCLUSIONS: When the soft-tissue envelope is compliant, has limited scar, and consists largely of healthy muscle with a good vascular supply, autogenous cancellous bone-grafting and stable internal plate fixation results in a high rate of union and improved upper limb function in patients with diaphyseal nonunion of the radius and/or ulna.

Adult↗
PubMed2004

Posttraumatic radial club hand.

Fifteen adult patients with an unstable ununited fracture of the distal third of the radius and severe radial deviation deformity resembling a radial club hand were retrospectively reviewed at an average of 25 months after operative treatment. There were eight women and seven men with an average age of 57 years (range, 33-79 years). The average duration of nonunion was 56 months (range, 6-252 months). Six patients had a concomitant fracture of the ulna and four had dislocation of the distal radioulnar joint. Three patients were treated with wrist arthrodesis and 12 with plate fixation and autogenous bone grafting. The distal ulna was excised and used for bone graft in eight patients. Correction of deformity was facilitated by z-lengthening of the brachioradialis and flexor carpal radialis in four patients and distraction histogenesis (llizarov) in two patients. One patient failed to heal the fracture and was treated with wrist arthrodesis. Functional alignment and use of the hand was restored in all patients.

Adult↗
PubMed2003

Modulation of muscle insulin resistance by selective inhibition of GSK-3 in Zucker diabetic fatty rats.

A role for elevated glycogen synthase kinase-3 (GSK-3) activity in the multifactorial etiology of insulin resistance is now emerging. However, the utility of specific GSK-3 inhibition in modulating insulin resistance of skeletal muscle glucose transport is not yet fully understood. Therefore, we assessed the effects of novel, selective organic inhibitors of GSK-3 (CT-98014 and CT-98023) on glucose transport in insulin-resistant muscles of Zucker diabetic fatty (ZDF) rats. Incubation of type IIb epitrochlearis and type I soleus muscles from ZDF rats with CT-98014 increased glycogen synthase activity (49 and 50%, respectively, P < 0.05) but did not alter basal glucose transport (2-deoxyglucose uptake). In contrast, CT-98014 significantly increased the stimulatory effects of both submaximal and maximal insulin concentrations in epitrochlearis (37 and 24%) and soleus (43 and 26%), and these effects were associated with increased cell-surface GLUT4 protein. Lithium enhanced glycogen synthase activity and both basal and insulin-stimulated glucose transport in muscles from ZDF rats. Acute oral administration (2 x 30 mg/kg) of CT-98023 to ZDF rats caused elevations in GSK-3 inhibitor concentrations in plasma and muscle. The glucose and insulin responses during a subsequent oral glucose tolerance test were reduced by 26 and 34%, respectively, in the GSK-3 inhibitor-treated animals. Thirty minutes after the final GSK-3 inhibitor treatment, insulin-stimulated glucose transport was significantly enhanced in epitrochlearis (57%) and soleus (43%). Two hours after the final treatment, insulin-mediated glucose transport was still significantly elevated (26%) only in the soleus. These results indicate that specific inhibition of GSK-3 enhances insulin action on glucose transport in skeletal muscle of the insulin-resistant ZDF rat. This unique approach may hold promise as a pharmacological treatment against insulin resistance of skeletal muscle glucose disposal.

Administration, Oral↗