Phillip C. Noble

Simple dislocation of the elbow in the adult. Results after closed treatment.

The long-term results after treatment of simple dislocation of the elbow in fifty-two adults were evaluated with regard to limitation of motion, pain, instability, and residual neurovascular deficit. All patients were treated with traditional closed reduction, but the duration of immobilization before commencement of active motion varied. Goniometric, photographic, and radiographic data were compiled for these patients, who had an average follow-up of 34.4 months. Despite the generally favorable prognosis for this injury, 60 per cent of the patients reported some symptoms on follow-up. A flexion contracture of more than 30 degrees was documented in 15 per cent of the patients; residual pain, in 45 per cent; and pain on valgus stress, in 35 per cent. Prolonged immobilization after injury was strongly associated with an unsatisfactory result. The longer the immobilization had been, the larger the flexion contracture (p less than 0.001) and the more severe the symptoms of pain were. The results indicate that early active motion is the key factor in rehabilitation of the elbow after a dislocation.

Use of a hinged silicone prosthesis for replacement arthroplasty of the first metatarsophalangeal joint.

A series of ninety consecutive total joint replacements of the first metatarsophalangeal joint with a flexible hinged prosthesis was reviewed after an average duration of follow-up of three years (range, twenty-four to sixty-one months). Although subjectively the results were satisfactory in most of the patients, and pain, the most common preoperative symptom, was reduced, mechanical failure of the implant was common, as determined radiographically. The frequency of failure of the implant and the extent to which it failed were related to the length of time that the implant had been in place. The range of motion of the metatarsophalangeal joint was decreased from normal. Dorsiflexion averaged 26 degrees and plantar flexion, 18 degrees. Callosities under at least one metatarsophalangeal joint were noted in fifty (69 per cent) of the feet that had a physical examination. Pedobarographic analysis of the distribution of plantar pressure revealed that none of the patients exerted weight-bearing pressures on the affected great toe. However, the subjective results were not significantly associated with radiographic evidence of failure of the implant. Despite its success in relieving the symptoms in our patients, we have abandoned this procedure because of the high and increasing rate of failure of the implant, as demonstrated radiographically.

Carpal arch alteration after carpal tunnel release

A retrospective clinical study quantitated postoperative widening of the transverse carpal arch after carpal tunnel release in a group of 50 patients. The relationship of this widening with postoperative pain, forearm circumference, grip strength, and wrist range of motion was evaluated. Mean widening of the transverse carpal arch after carpal tunnel release is 10.4% or 2.7 mm. A direct relationship exists between widening of the transverse carpal arch and loss of grip strength. Residual pain, forearm circumference, and wrist range of motion are not related to widening of the transverse carpal arch.

Biomechanical Consequences of Sequential Plantar Fascia Release

Plantar fascia release has long been a mainstay in the surgical treatment of persistent heel pain, although its effects on the biomechanics of the foot are not well understood. With the use of cadaver specimens and digitized computer programs, the changes in the medial and lateral columns of the foot and in the transverse arch were evaluated after sequential sectioning of the plantar fascia. Complete release of the plantar fascia caused a severe drop in the medial and lateral columns of the foot, compared with release of only the medial third. Equinus rotation of the calcaneus and a drop in the cuboid indicate that strain of the plantar calcaneocuboid joint capsule and ligament is a likely cause of lateral midfoot pain after complete plantar fascia release.

Security of Knots Tied with Ethibond, Fiberwire, Orthocord, or Ultrabraid:

Background The security of several popular arthroscopic knots to prolonged, incremental, cyclic loads is unknown, as is the security of knots tied with newer, superstrong sutures. Hypothesis Some arthroscopic knots are as secure as openly tied square knots, and knots tied with superstrong sutures are more secure than those tied with braided polyester. Some arthroscopic knots are significantly bulkier than openly tied square knots. Study Design Controlled laboratory study. Methods Five types of openly tied knots (3-throw square, 4-throw square, 5-throw square, 5-throw slip, open SAK [simple arthroscopic knot]), 6 complex arthroscopic knots backed with 3 reversed half-hitches with alternating posts (RHAPs) (SMC, Weston, taut-line hitch, Tennessee slider, Roeder, Duncan loop), and 2 stacked half-hitch (SHH) arthroscopic knots (surgeons [S=S=S//xS//xS//xS], SAK [S=S//xSxS//xS]) were tied using No. 2 Ethibond around 2 aluminum rods, which were pulled apart with stepwise, incremental, cyclic loads to a maximum force of 120 N (2250 total cycles). Then, 5-throw square knots openly tied with No. 2 Fiberwire, Orthocord, or Ultrabraid were subjected to the stepwise, incremental, cyclic loading protocol extended to a 260-N load level. Before mechanical testing, the height (maximum diameter) of each knot was measured with digital calipers. Results For Ethibond, the openly tied 3-throw square knots (56.2 ± 21.4 N) and 5-throw slip knots (49.9 ± 26.9 N) reached clinical failure (3 mm of laxity) at significantly lower loads (P < .05) than openly tied 5-throw square knots (90.8 ± 6.5 N), whereas the openly tied SAK (82.3 ± 9.4 N) and 4-throw square (84.3 ± 11.6 N) and all arthroscopically tied knots reached 3 mm of laxity at statistically similar loads. Five-throw square knots openly tied with Fiberwire or Orthocord reached 3 mm of laxity at much higher loads (194.9 ± 28.4 N and 168.4 ± 8.6 N, respectively) than those tied using Ethibond (P < .001 for each comparison), but there was no significant difference in performance between Fiberwire knots and Orthocord knots. Although Ultrabraid square knots also were stronger than those tied with Ethibond (137.9 ± 15.9 N, P < .005), they were not as secure as those tied with Orthocord or Fiberwire (P < .05). Compared with the 5-throw square knots, all arthroscopic knots were significantly bulkier. Especially bulky knots were the Duncan loop and the taut-line hitch. Orthocord square knots demonstrated bulkiness similar to Ethibond square knots, whereas Fiberwire and Ultrabraid square knots were significantly bulkier. Conclusions For braided suture, 5-throw knots optimize square knot security. Open or arthroscopic slip knots can achieve similar security with post switching and loop reversal. Fiberwire, Orthocord, or Ultrabraid openly tied square knots offer greater security than those tied with Ethibond. Arthroscopic knots vary in their bulkiness, but all are significantly bulkier than 5-throw openly tied square knots. Square knots openly tied with Fiberwire or Ultrabraid tend to be bulkier than if tied with Ethibond or Orthocord, which are similar to each other. Clinical Relevance The 5-throw openly tied square knot remains the gold standard, although the openly tied SAK offers similar security when tying in a hole. Arthroscopic knots, whether complex knots backed up by 3 RHAPs, the 6-throw surgeons knot, or the 5-throw SAK, give security similar to the standard. Square knots tied with the newer sutures in open fashion are more secure than if tied with braided polyester. Using lower profile knots may be especially important when employing Fiberwire or Ultrabraid, as these sutures tend to result in bulkier knots than those tied with Ethibond or Orthocord.

Calcaneocuboid stability: a clinical and anatomic study.

Injuries to the midtarsal joints are relatively uncommon and often unrecognized entities. Acute and chronic instability patterns to the calcaneocuboid joint can occur from such injuries. No previous determinations of normal calcaneocuboid laxity have been reported. Utilizing a previously described technique, stress radiographs were performed in human cadaveric specimens following serial sectioning of the ligamentous supports of the calcaneocuboid joint. Significant differences in calcaneocuboid gap and angle occurred between unstressed and stressed conditions. Cadaveric specimen testing determined that the dorsal and plantar calcaneocuboid ligaments both provide significant contributions to joint stability. Prior to defining pathologic states of joint laxity, normal ranges of stability must be determined. By more clearly defining normal stability of the calcaneocuboid joint and its ligamentous contributions, greater insight into the diagnosis and treatment of calcaneocuboid instability can be obtained.

Effect of early full weight-bearing after joint injury on inflammation and cartilage degradation.

BACKGROUND Early full weight-bearing after an acute osteochondral injury avoids problems associated with immobility but may also be harmful by amplifying the inflammatory response. To investigate these effects, we developed an in vivo model of subchondral trauma. METHODS After an impact injury to the femoral condyle, fourteen dogs were randomized to immediate full weight-bearing or to four weeks of minimal weight-bearing before full weight-bearing. Synovial fluid was sampled by aspiration at one, two, four, eight, twelve, sixteen, twenty, and twenty-four weeks. Neutrophils, monocytes, and lymphocytes were enumerated, and the concentrations of tumor necrosis factor-alpha, interleukin-10, nitric oxide, matrix metalloproteinases, and glycosaminoglycans were measured. RESULTS Compared with the findings for uninjured joints, the synovial fluid from the impacted joints of full-weight-bearing dogs had significantly higher peak concentrations of neutrophils (p = 0.0006 at one week), mononuclear leukocytes (p = 0.001 at four weeks), tumor necrosis factor-alpha (p = 0.001 at one week), nitric oxide (p = 0.001 at one week), matrix metalloproteinases (p = 0.008 at one week), and glycosaminoglycans (p = 0.002 at four weeks and p = 0.001 at six months). The size of the bone bruise correlated with the peak concentrations of tumor necrosis factor-alpha (r2= 0.89, p = 0.007; Spearman rank test), matrix metalloproteinases (r2= 0.96, p = 0.0004), and glycosaminoglycans (r2= 0.96, p = 0.0004). However, restriction to minimal weight-bearing for four weeks after the injury led to a significant reduction in the synovial fluid concentrations of neutrophils (p = 0.007 at one week and p = 0.01 at two weeks), tumor necrosis factor-alpha (p = 0.0006 to 0.02 during the first four weeks), nitric oxide (p = 0.001 to 0.04 during the first four weeks), and matrix metalloproteinases (p = 0.007 to 0.01 from the second week to the eighth week). In contrast, interleukin-10 concentrations were significantly higher (p = 0.002 at one week) and glycosaminoglycan levels remained at normal levels in animals that were restricted from immediate full weight-bearing after the injury. CONCLUSIONS The magnitude of the inflammatory response is proportional to the size of the bone bruise. Restriction to minimal weight-bearing for four weeks reduces the magnitude of the inflammatory response and the cartilage degradation following articular cartilage impact injury. CLINICAL RELEVANCE Strategies to minimize mechanical stress during the early postinjury period may help to preserve cartilage integrity and forestall the development of osteoarthritis.

Evaluation of an electrogoniometric instrument for measurement of laxity of the knee

Eight lower extremities from cadavera were tested for anterior-posterior laxity in two positions before and after transection of the anterior cruciate ligament. At critical points in the tests, electrogoniometric and radiographic measurements of tibiofemoral translation were compared. By direct measurement, we determined the accuracy of the radiographic method to +/- 0.4 millimeter (95 per cent) in measuring anterior-posterior translations of the tibia with respect to the femur. The electrogoniometer estimated displacement of the tibia with respect to the femur during the anterior drawer test to be 3.5 +/- 8.2 millimeters at 90 degrees of flexion of the knee and 11.1 +/- 16.1 millimeters at 30 degrees of flexion. Direct comparison of these measurements with those obtained by means of the radiographic technique showed that the electrogoniometer tended, on average, to overestimate the tibial translation. The amount of overestimation was 0.7 millimeter for intact knees and 1.9 millimeters after sacrifice of the anterior cruciate ligament. Despite this small average error in measurement of tibial translation, the difference between individual electrogoniometric and radiographic measurements varied greatly, with a 95 per cent confidence limit of +/- 5.5 millimeters. The error of the electrogoniometric measurements varied with the angle of flexion of the knee during testing, both the accuracy and the reliability of the electrogoniometric measurements being greatly diminished at 30 degrees of flexion. The electrogoniometric method also tended to overestimate tibial internal rotation (by an average of 10.5 degrees) and external rotation (by an average of 9.3 degrees); the reliability of these measurements was +/- 6.9 degrees.(ABSTRACT TRUNCATED AT 250 WORDS)

Isometry measurements in the knee with the anterior cruciate ligament intact, sectioned, and reconstructed.

When assessing isometry during anterior cruciate lig ament surgery, it is assumed that points determined to be isometric remain so after reconstruction. We sought to evaluate if isometric measurements vary with the status of the anterior cruciate ligament. A computer ized electronic isometer was used to measure the magnitude and pattern of change in separation dis tance between a constant point in the tibial insertion of the anterior cruciate ligament and five positions within the femoral insertion with the anterior cruciate ligament intact, sectioned, and reconstructed. For the center position, the magnitude and pattern of the change in separation distance was physiologically isometric in all conditions (maximal length change, 3.0 mm). For the posterior position, the isometry pattern remained phys iologic in each condition, and the magnitude of the separation distance was nearly isometric in all condi tions (maximal length change, 3.7 mm). The superior and inferior positions had similar isometric meas urements in the intact and sectioned conditions but significantly different measurements after anterior cru ciate ligament reconstruction. Intraoperative assess ment of isometry at positions in the center or posterior portion of the anterior cruciate ligaments femoral in sertion provides useful information that is not altered by reconstruction. For superior and inferior positions, however, points found to be isometric in the anterior cruciate ligament-deficient knee did not remain isomet ric after reconstruction.

External stabilization of the anterior cruciate ligament deficient knee during rehabilitation

Using cadaveric specimens, we studied the effect of ACL deficiency upon anterior tibial translation during extension of the knee joint. Five knees were loaded via the quadriceps mechanism until flexion angles of 10°, 25°, 40°, and 60° were attained. At each angle, the anterior-posterior position of the tibia was documented with biplane radiography, both before and after division of the ACL. In every specimen, anterior tibial translation increased with loss of the ACL and was greatest at 25° of flexion, where an average displacement of 3.3 mm was observed. Subluxation was not significant at flex ion angles exceeding 60°, regardless of ACL deficiency. We also examined the effect of an external restraining force on tibial subluxation in the ACL deficient knee. Posteriorly directed forces of 0 N, 45 N (10 pounds), 90 N (20 pounds), 135 N (30 pounds), and 225 N (50 pounds) were applied to the tibia at the level of the tibial tubercle. Anterior subluxation was eliminated through application of forces ranging from a maximum of 106 N (23.6 pounds) at 10° to only 13 N (2.9 pounds) at 60°.