Biomedical subjects

P A Dowdy

Publications and source records attributed to P A Dowdy.

10 recordsLinked to original sources

PubMed1998

Bone sarcoma diagnosed at the time of reconstructive hip surgery.

OBJECTIVE: To describe the clinical course of a group of patients in whom sarcoma of the proximal femur was diagnosed at the time of reconstructive hip surgery. DESIGN: A retrospective case series. SETTING: Final management of all patients took place at a tertiary care centre. PATIENTS AND INTERVENTIONS: Six consecutive patients with sarcoma of the proximal femur diagnosed at the time of reconstructive hip surgery. The mistaken diagnoses made before surgery were benign tumour (2 patients), avascular necrosis (2 patients), subtrochanteric fracture due to metastasis (1 patient) and granuloma from a loose hip implant (1 patient). The final diagnosis was osteosarcoma in 3 patients and chondrosarcoma in 3. Three patients with high-grade sarcoma received neoadjuvant chemotherapy followed by femoral or pelvic resection, or both, and reconstruction. Two patients with chondrosarcoma underwent wide excision of the tumour with allograft or modular implant reconstruction. One patient with widespread metastasis received only palliative chemotherapy. MAIN OUTCOME MEASURES: Overall survival with respect to oncologic and functional results of treatment. RESULTS: Two patients (1 who received only palliative chemotherapy) died after 5 and 21 months' followup, respectively. Average follow-up for the remaining 4 patients was 65.2 months (range from 51 to 75 months). They were disease free at latest follow-up. One patient required amputation for septic complications related to the reconstruction. CONCLUSIONS: Limb salvage surgery for sarcoma of the proximal femur is challenging when the diagnosis is made at the time of reconstructive surgery rather than through an appropriately planned biopsy. However, this series suggests that limb preservation is feasible and that hindquarter amputation is not the only solution.

Adult↗

PubMed1997

Uncemented total hip arthroplasty in patients 50 years of age or younger.

The results of a consecutive series of uncemented total hip arthroplasties in patients 50 years or younger are reviewed. There were 41 total hip arthroplasties in 36 patients at an average follow-up period of 5.3 years. Average patient age was 42 years at the time of implantation. Preoperative Harris hip score (HHS) averaged 39/100; the final HHS averaged 93. Radiographic evaluation revealed that the femoral stems were all solid, with no progressive subsidence, reactive lines, or osteolysis. Twenty of the hips (49%) demonstrated evidence of polyethylene wear. There was significant acetabular osteolysis in 12 of these 20 hips. Five of the acetabular cups were definitely loose; 1 was possibly loose. Three of the patients underwent revision surgery for acetabular loosening and/or osteolysis. It is concluded from this study that the femoral stem is excellent but that the original acetabular component and polyethylene locking mechanism are poor and made even worse with the use of a titanium femoral head.

Acetabulum↗

PubMed1996

Noninvasive ankle distraction: relationship between force, magnitude of distraction, and nerve conduction abnormalities.

Seven healthy volunteers (14 ankles; four males, 3 females) with no history of ankle or foot pathology were placed in a modified beach chair position on an operating table for ankle distraction using a noninvasive ankle distractor. In-line traction of 0 to 225 N (50 lb) in 22.5-N (5-lb) increments was applied to the ankle. A direct lateral radiograph was obtained at each distraction force. The joint space was measured on the lateral radiographs using electronic microcalipers. Surface recordings of the superficial peroneal, deep peroneal dorsal digital cutaneous, and sural nerves were obtained. The ankle joint space increased progressively from an average 3.1 mm with no force applied to an average 4.2 mm with 225 N (50 lb) distraction force applied. The maximum joint distraction averaged 1.3 mm (range, 0.35 to 2.35 mm). The sensory amplitudes were diminished or absent with increasing time and force of distraction. The decreased amplitudes were most marked after 1 hour of distraction with 135 N (30 lb) or greater distraction force. This correlated with symptoms of paresthesias. The superficial and deep peroneal cutaneous nerves were affected to a much greater extent than the sural nerve. The amplitudes quickly returned to normal values with the weight being released from the ankle. The noninvasive ankle distractor safely increased ankle joint space by more than 1 mm. Distraction with 135 N (30 lb) or more for 1 hour is associated with reversible nerve conduction changes. Based on these findings, we recommend using the noninvasive ankle distraction apparatus for ankle arthroscopy, with up to 135 N (30 lb) of traction applied to the foot for up to 1 hour. Greater force, applied for longer periods, is associated with increasing nerve conduction abnormalities.

Adolescent↗

PubMed1996

Intrafocal (Kapandji) pinning of unstable distal radius fractures: a preliminary report.

Seventeen consecutive patients (17 wrists) who underwent intrafocal pinning of unstable distal radius fractures, as described by Kapandji, were retrospectively reviewed at a mean of 42 weeks after surgery (range, 13-88 weeks). The patients were immobilized for 6 weeks postoperatively. All patients were assessed by a single physician and were asked a set of questions regarding subjective and functional status. All patients underwent physical examination of their upper extremities, and bilateral wrist PA and lateral x-rays were taken. There were 13 females and four males; the average age was 49 years. Ten dominant and seven nondominant extremities were involved. Average volar tilt on follow-up lateral wrist radiography was 7 degrees. This compares with -20 degrees at initial presentation, -12 degrees preoperatively, 6 degrees immediately postoperatively, and 10 degrees in the normal wrists. Radial shortening (average) was -2 mm at initial presentation, -1mm preoperatively, 1 mm postoperatively, 0 mm at follow-up, and 1 mm in the normal wrists. Radial inclination was 17 degrees initially, 20 degrees preoperatively, 23 degrees immediately postoperatively, 23 degrees on follow-up, and 24 degrees in the normal wrists. There was a trend for patients with osteopenic bone to lose their postoperative reduction. However, this was not statistically significant. Patients older than 65 years of age had significantly inferior radiologic results. Loss of pronation and supination averaged 2 degrees (range 0-10 degrees) compared with the uninjured wrist. Loss of dorsiflexion averaged 6.5 degrees, and palmar flexion averaged 7.6 degrees. The patients' subjective complaints were minimal. Average pain on visual analog scale (VAS) was 0.44/10. Function measured 8.64/10 (VAS). Sixteen of the patients were happy with the surgery and the outcome of their wrists. Complications included extensor tendon rupture (one patient), pin migration requiring premature removal (one patient), and initial loss of reduction requiring reoperation (one patient). Intrafocal pinning of unstable distal radius fractures provides an effective means to stabilize these complex injuries. Early follow-up suggests that the patients have a satisfactory functional outcome. The complications in this series were preventable. Intrafocal pinning should be added to the surgical armamentarium in treating distal radius fractures.

Adolescent↗

PubMed1995

The midline posterior elbow incision. An anatomical appraisal.

The formation of a painful neuroma after operations on the medial or lateral sides of the elbow is a common problem. Our aim was to determine the relationship of the cutaneous nerves to the three usual skin incisions around the elbow. In 18 freshly frozen cadaver arms we made three standard 16 cm incisions in the skin medially, laterally, and posteriorly and explored them using loupe magnification. The number of nerves crossing each incision was determined by gross observation and their diameter measured by electronic microcallipers. In ten arms, biopsies of the nerves in each incision were sent for histological examination. We found significantly more cutaneous nerves crossing the medial and lateral incisions than the posterior. The diameter of the nerves crossing the posterior incision was significantly smaller than those crossing the lateral incision. Cutaneous nerves are at considerable risk of injury when medial or lateral incisions are used to approach the elbow, but the posterior approach carries less hazard. The routine use of the posterior incision may reduce the incidence of symptomatic paraesthesia and the formation of a painful neuroma after operation.

Analysis of Variance↗

PubMed1994

The palmar cutaneous branch of the median nerve and the palmaris longus tendon: a cadaveric study.

The purpose of this study was to determine the frequency with which the palmar cutaneous branch of the median nerve passes through the palmaris longus tendon. Fifty-two wrists (27 cadavers) were dissected. In three wrists the palmaris longus tendon was absent. The palmar cutaneous branch was seen to course through the fibers of the palmaris longus in two specimens (different cadavers). The nerve passed through the tendon 1 and 1.5 cm proximal to its insertion into the palmar aponeurosis. In the presence of this anomaly the palmar cutaneous branch of the median nerve is at risk of injury during harvesting of the palmaris longus tendon for grafts. To avoid injury, we recommend transecting the tendon 2 cm proximal to its insertion into the palmar aponeurosis.

Cadaver↗

PubMed1993

Shoulder instability. An analysis of family history.

A family history of shoulder instability in first-degree relatives was found in 24 of 100 patients who had been operated on for recurrent anterior shoulder instability. The patients with and without a family history were similar in respect of sex ratio, age at first dislocation and age at operation. The initial dislocation was non-traumatic in 22% of the patients with and in 13% of those without a positive family history (p = 0.3). Postoperative recurrence of instability was experienced by 34% of patients with and 33% of those without a family history (p = 0.9). In those with a family history, 13% of the recurrences were dislocations and 87% were subluxations. In patients without a family history 52% of the recurrences were dislocations and 48% were subluxations (p < 0.05). The contralateral shoulder was unstable in 50% of the patients with a family history and in 26% of those without (p = 0.03).

Adult↗

PubMedDate not supplied

Recurrent anterior shoulder instability.

The purpose of this study was to compare 2 radiographic methods for measuring anteversion and to determine whether glenoid anteversion is a significant factor in recurrence of instability after anterior repair. West Point axillary roentgenograms were obtained in 128 patients (138 shoulders) at a mean of 9 years after surgery. Two methods to measure glenoid anteversion were compared: The angle between the glenoid and the body of the scapula, and the angle between the glenoid and the posterior margin of the acromion. There was less variation in the measurements using the glenoid margin-posterior acromion angle. By this method, anteversion was 11 degrees +/- 4 degrees for the 15 patients with multiple (2 or more) recurrences, 8 degrees +/- 3 degrees for the 15 patients with 1 recurrence, and 6 degrees +/- 5 degrees for the 109 patients with no recurrences. Although these differences are statistically significant (P = 0.003), they probably are not clinically important because they are small (mean of only 5 degrees). The differences obtained by measuring the angle between the glenoid and the body of the scapula were not statistically significant.

Acromion↗

PubMedDate not supplied

Magnetic resonance imaging evaluation of the rotator cuff tendons in the asymptomatic shoulder.

Thirty shoulders in 20 volunteers (average age, 29 years; range, 17 to 49) with no shoulder symptoms or known abnormalities were scanned using magnetic resonance imaging. All scans were interpreted by one radiologist who was blinded to clinical data. Appearance of rotator cuff tendons on the images was graded. Grade 0 was normal, homogeneous low signal intensity structure. Grade 1 lesion was focal, linear, or diffuse intermediate signal through the tendon. Grade 2 lesion was high signal intensity within the tendon and less than full thickness. Grade 3 was high signal intensity through full thickness of the tendon. No supraspinatus or infraspinatus tendons were grade 0 (normal); all supraspinatus and infraspinatus tendons had grade 1 changes through the tendons; and 7 of 30 (23%) of the tendons had grade 2 changes. None of the 30 shoulders had grade 3 changes in the rotator cuff tendons. There is a wide array of abnormal magnetic resonance imaging signals in shoulders of young asymptomatic individuals, but they do not have full-thickness rotator cuff tears (grade 3 lesion). Nonenhanced magnetic resonance imaging may be of limited value in defining rotator cuff injury in a patient with shoulder pain unless a full-thickness rotator cuff tear is suspected clinically.

Adolescent↗

PubMedDate not supplied

The effect of cast immobilization on meniscal healing. An experimental study in the dog.

A 1.5-cm longitudinal, full-thickness incision was made in the vascularized portion of the medial meniscus in 20 adult dogs and anatomically repaired. Postoperatively, the animals were either placed in a long leg cast (N = 9) or mobilized immediately (N = 11). The animals were sacrificed at 2 weeks (6 dogs), 4 weeks (6 dogs), or 10 weeks (8 dogs). Five medial menisci from the nonoperated side were used as controls. Collagen content was measured using a digital image analysis system, and the collagen percentage in the repair tissue in each postoperative treatment group was compared. In the 2-week and 4-week groups, there was no statistically significant difference in the percentage of collagen between those animals immobilized versus those that had early mobilization. The animals in the 10-week group that were mobilized had a significantly greater collagen percentage in the healing meniscal incision than those that were cast immobilized (44.6% +/- 10% versus 27.0% +/- 11%, P < 0.0001). There was no significant difference in the collagen percentages between the mobilized 10-week group and the contralateral control menisci group. All other menisci had a decreased collagen percentage compared with the controls. Prolonged immobilization decreases collagen formation in healing menisci. Thus, our results suggest that patients undergoing isolated meniscal repair either be immediately mobilized after surgery or immobilized for short periods only.

Animals↗