Ludvig Fjeld Solheim

The Piriformis Muscle Syndrome: Sciatic Nerve Entrapment Treated with Section of the Piriformis Muscle

The piriformis muscle syndrome, a term applied to an abnormal condition of the piriformis muscle, is characterized by symptoms and signs due to sciatic nerve entrapment at the greater sciatic notch. Two patients with this syndrome, successfully treated with section of the piriformis muscle, are reported. The piriformis muscle syndrome should be suspected as part of the differential diagnosis in cases of low back and hip or thigh pain.

FEMORAL AND SCIATIC NEUROPATHIES AFTER TOTAL HIP ARTHROPLASTY

Six patients with peripheral nerve lesions after total hip replacements were reviewed. The incidence of peripheral nerve lesions was six out of 825, i.e. 0.7 per cent. The neuropathies, four sciatic, one femoral and one combined femoral and sciatic, were due to damage by the reamer in one case, haemorrhage in two, whereas the cause was unknown in three patients. After conservative treatment and 1-5 years follow-up the recovery was classified as good in three, fair in one and poor in two patients.

Chronic Recurrent Multifocal Osteomyelitis: A New Clinical-Radiological Syndrome

Chronic recurrent multifocal osteomyelitis is characterized clinically and radiologically by multiple, sometimes symmetrical, infectious bone lesions and a prolonged course over several years with relapses and new lesions. The distribution of the osteolytic bone lesions follows the pattern of acute haematogenous osteomyelitis in infancy and childhood. The aetiology and pathogenesis of this disease is unclear. A 5-year-old girl with this disease and 19 similar cases from the literature are reviewed.

Bone changes after castration in rats. A model for osteoporosis

Bone changes 6-12 weeks after castration have been studied in 25 female and 27 male middle-aged rats. Castrated female rats gained more weight than their controls, but had decreased bone density and calcium and hydroxyproline content per cm3 bone volume of tibia. Castrated male rats did not differ from controls regarding body weight and the bone parameters. No influence of castration on the mechanical strength of the femora could be detected in either sex. At 2 weeks after castration, the circulating levels of immunoreactive calcitonin (iCT) were decreased in female rats compared to controls. In contrast, iCT was increased both in castrated male and female rats 10 weeks later. We conclude that castration of 6-month-old female rats causes osteoporosis, and therefore represents a promising experimental model for studying postmenopausal bone loss.

Compression of the Suprascapular Nerve After Fracture of the Scapular Notch

A 32-year-old man with a fracture of the scapular notch associated with a lesion of the suprascapular nerve is reported. A nerve decompression operation was performed 20 months after the injury with relief of pain. The possibility that residual disability following a fracture of the scapula can be due to a lesion of the suprascapular nerve is underlined. The value of X-ray examination with projections visualizing the notch and diagnostic local anaesthetic block of the nerve passing through the notch are emphasized. Primary wide resection of the scapular notch is a preferable procedure preventing recurrence of nerve compression symptoms.

Chronic Lateral Instability of the Ankle: Method of Reconstruction Using the Achilles Tendon

Reconstruction of the lateral ankle ligaments ad modum Støren, using the medial one third of the Achilles tendon as a nourished transplant is a relatively unknown procedure. Thirty patients operated on using this technique have been evaluated. The mean observation time was 4 years (range 1/2--16 years). All patients but one had a stable ankle joint and were satisfied. One was reoperated after sustaining a new injury 6 months after the original operation. The method described is a good alternative to other methods of ligamentous reconstruction. The procedure also stabilizes the subtalar joint and corrects recurrent subluxation of the peroneal tendons.

Bone formation enhanced by induction: Bone growth in titanium implants in rats

Bone-inducing materials have been investigated for the purpose of augmenting bone formation in implants made of porous fiber titanium. The bone-inducing materials used were: (1) Bone from the iliac crest of inbred rats (isografts), (2) Antigen-extracted, autolyzed, demineralized bone from outbred rats (AAA bone a.m. Urist), and (3) AAA bone combined with bone marrow from inbred rats. Tubes of fiber titanium were packed with bone-inducing materials and implanted in the back musculature of inbred rats. Bone formation was assessed by labelling with 3H-proline (collagen synthesis) and 47Ca (mineral deposit) and by content of calcium of the harvested implants. Isografts and AAA bone with marrow yielded a substantial amount of new bone. Without the marrow, AAA bone yielded very small amounts of new bone.

Comparison of ceramic and titanium implants in cats

The mechanical strengths of the bone-implant interfaces of titanium coated with glass ceramic and pure titanium implants were compared. The glass ceramic had a chemical composition similar to 45S5F Bioglass. Cylindrical implants were placed in feline femurs. Six weeks later the strength of the fixation was tested using pull-out tests. Energy dispersive X-ray microanalysis was applied to pursue any possible relationship between mechanical strength and changes in elemental composition at the bone-implant interface. The ultimate shearing force for the pure titanium implants was higher than for the implants coated with glass ceramic. Also, the glass ceramic coating was partly degraded by the tissues. Evidently, the mechanical properties of the glass ceramic to bone interface were governed by some sort of chemical reaction that implied transfer of elements from the implant to bone. It appears that this reaction eventually will destroy the coating which makes this kind of material unsuitable for prosthesis fixation.

Effects of acetylsalicylic acid and naproxen on the synthesis and mineralization of collagen in the rat femur

SummaryThe influence of acetylsalicylic acid (ASA) and naproxen on the biochemical properties of intact growing femora in young male rats was studied. The medication periods were 9 and 18 days. At an ASA dose of 150 mg/kg/12 h the rate of collagen synthesis and the rate of mineral incorporation decreased and were impaired by about 10% compared with controls after 18 days. The dry weights and contents of collagen and calcium were not influenced after 9 days, but were reduced by 4%–7% after 18 days. A higher solubility of collagen (7%) was also found at the end of the study. In rats that received ASA at 100 mg/kg/12 h no significant differences were observed. A naproxen dose of 20 mg/kg/12 h reduced the rate of mineral deposition after 18 days, but had no other detectable effects on bone. The results indicate that ASA inhibits bone formation.ZusammenfassungEs wurde der Einfluß analysiert, den eine 18tägige Behandlung mit Azetylsalizylsäure (ASS) and Naproxen auf den Stoffwechsel des wachsenden Oberschenkelknochens junger männlicher Ratten hat. ASS in einer Dosierung von 150 mg/kg/12 Std bewirkte nach 18 Tagen eine Hemmung der Kollagensynthese and des Mineraleinbaus. Die entsprechenden Trockengewichte sowie der Kollagenund Calziumgehalt waren gleichfalls vermindert, während die lösliche Kollagenfraktion zunahm. ASS und Naproxen in Dosen von 100 bzw. 20 mg/kg/12 Std zeigte keine Wirkungen, bzw. nur Abnahme des Mineraleinbaus. Diese Studie zeigt, daß die Knochenneubildung durch ASS herabgesetzt wird.

Osteogenesis promoted by bone matrix combined with marrow: Titanium implants studied in rats

We evaluated the bone-forming potential of isogeneic bone marrow combined with antigen-extracted, autolyzed allogeneic bone matrix (AAA bone a.m. Urist). The purpose of the experiment was to evaluate bone-inducing materials for application in orthopaedic devices designed for fixation by bone ingrowth into a porous surface. The bone-forming materials were packed into tubes of porous fiber titanium and placed in the back musculature of rats for 12 or 25 days. At 12 days the combination of bone marrow and AAA bone had produced more bone than marrow only. At 25 days, however, there was no difference. The bone-inducing materials produced substantial amounts of new bone, and may become an adjuvant for achieving fixation by bone ingrowth. In particular, a combination of AAA bone and marrow might enhance fixation at a very early postoperative stage.