Oliver Grundnes

Lumbar instrumented fusion compared with cognitive intervention and exercises in patients with chronic back pain after previous surgery for disc herniation: a prospective randomized controlled study.

Abstract The effectiveness of lumbar fusion for chronic low back pain after surgery for disc herniation has not been evaluated in a randomized controlled trial. The aim of the present study was to compare the effectiveness of lumbar fusion with posterior transpedicular screws and cognitive intervention and exercises. Sixty patients aged 25–60 years with low back pain lasting longer than 1 year after previous surgery for disc herniation were randomly allocated to the two treatment groups. Experienced back surgeons performed transpedicular fusion. Cognitive intervention consisted of a lecture intended to give the patient an understanding that ordinary physical activity would not harm the disc and a recommendation to use the back and bend it. This was reinforced by three daily physical exercise sessions for 3 weeks. The primary outcome measure was the Oswestry Disability Index (ODI). Outcome data were analyzed on an intention‐to‐treat basis. Ninety‐seven percent of the patients, including seven of eight patients who had either not attended treatment (n = 5) or changed groups (n = 2), completed 1‐year follow‐up. ODI was significantly improved from 47 to 38 after fusion and from 45 to 32 after cognitive intervention and exercises. The mean difference between treatments after adjustment for gender was −7.3 (95% CI −17.3 to 2.7, p = 0.15). The success rate was 50% in the fusion group and 48% in the cognitive intervention/exercise group. For patients with chronic low back pain after previous surgery for disc herniation, lumbar fusion failed to show any benefit over cognitive intervention and exercises.

The importance of the hematoma for fracture healing in rats

In 3 groups of rats, bilateral femoral fractures were produced. The fracture hematoma was removed on one side after 30 min, 2 days and 4 days in the 3 groups, respectively. The fractures were mechanically tested at 4 weeks. When the fracture hematoma was removed early, callus production, bending moment, and fracture energy were decreased. Removal of the hematoma at Day 2 or 4 impaired fracture healing even more, as both bending moment, bending rigidity and fracture energy were greatly decreased compared to the control fractures. We conclude that the fracture hematoma favors healing; removal of the hematoma after some days is more harmful to healing than when the hematoma is removed in the initial phase.

Surgery with disc prosthesis versus rehabilitation in patients with low back pain and degenerative disc: two year follow-up of randomised study

Objective To compare the efficacy of surgery with disc prosthesis versus non-surgical treatment for patients with chronic low back pain. Design A prospective randomised multicentre study. Setting Five university hospitals in Norway. Participants 173 patients with a history of low back pain for at least one year, Oswestry disability index of at least 30 points, and degenerative changes in one or two lower lumbar spine levels (86 patients randomised to surgery). Patients were treated from April 2004 to September 2007. Interventions Surgery with disc prosthesis or outpatient multidisciplinary rehabilitation for 12-15 days. Main outcome measures The primary outcome measure was the score on the Oswestry disability index after two years. Secondary outcome measures were low back pain, satisfaction with life (SF-36 and EuroQol EQ-5D), Hopkins symptom check list (HSCL-25), fear avoidance beliefs (FABQ), self efficacy beliefs for pain, work status, and patients’ satisfaction and drug use. A blinded independent observer evaluated scores on the back performance scale and Prolo scale at two year follow-up. Results The study was powered to detect a difference of 10 points on the Oswestry disability index between the groups at two years. At two years there was a mean difference of −8.4 points (95% confidence interval −13.2 to −3.6) in favour of surgery. In the analysis of prespecified secondary outcomes, there were significant differences in favour of surgery for low back pain (mean difference −12.2, −21.3 to −3.1), patients’ satisfaction (63% (n=46) v 39% (n=26)), SF-36 physical component score (mean difference 5.8, 2.5 to 9.1), self efficacy for pain (mean difference 1.0, 0.2 to 1.9), and the Prolo scale (mean difference 0.9, 0.1 to 1.6). There were no significant differences in return to work, SF-36 mental component score, EQ-5D, fear avoidance beliefs, Hopkins symptom check list, drug use, and the back performance scale. One serious complication of leg amputation occurred during surgical revision of a polyethylene dislodgement. The drop-out rate was 20% (34) and the crossover rate was 6% (5). Conclusions Surgical intervention with disc prosthesis for chronic low back pain resulted in a significantly greater improvement in the Oswestry score compared with rehabilitation, but this improvement did not clearly exceed the prespecified minimally important clinical difference between groups of 10 points, and the data are consistent with a wide range of differences between the groups, including values well below 10 points. The potential risks of surgery and the substantial amount of improvement experienced by a sizeable proportion of the rehabilitation group also have to be incorporated into overall decision making. Trial registration NCT 00394732.

Blood flow and mechanical properties of healing bone : femoral osteotomies studied in rats

In male Wistar rats, a transverse osteotomy at the midshaft of the femur was made, and the acute effects on bone flow were measured before and after reaming. Flow and mechanical variables in the healing bones were measured at 4, 8, and 12 weeks following osteotomy. Osteotomy reduced total bone blood flow by about 50 percent, and cortical flow in the diaphysis by approximately 40 percent. Cortical flow was equally diminished in the mid-diaphysis and in the osteotomy area, and no differences between the proximal and distal diaphyseal flows were found. Reaming of the osteotomized bones did not lead to any further flow reduction. At 4 weeks, total bone flow was more than doubled; increases were found in every segment of the fractured bone, and a more than 10-fold increase in the callus area was seen. At the end of the experiment, the femurs had regained 83 percent of their normal strength, 88 percent of normal rigidity and 78 percent of normal fracture energy. At this time total bone flow was marginally increased, flows in the proximal and the distal diaphyses were almost normalized, while a nearly 3-fold increase was still found in the callus area. Flow in the callus area gradually decreased during healing, and regression analysis demonstrated a negative correlation between callus flow and mechanical properties.

Effect of Glucosamine on Pain-Related Disability in Patients With Chronic Low Back Pain and Degenerative Lumbar Osteoarthritis: A Randomized Controlled Trial

CONTEXT Chronic low back pain (LBP) with degenerative lumbar osteoarthritis (OA) is widespread in the adult population. Although glucosamine is increasingly used by patients with chronic LBP, little is known about its effect in this setting. OBJECTIVE To investigate the effect of glucosamine in patients with chronic LBP and degenerative lumbar OA. DESIGN, SETTING, AND PARTICIPANTS A double-blind, randomized, placebo-controlled trial conducted at Oslo University Hospital Outpatient Clinic, Oslo, Norway, with 250 patients older than 25 years of age with chronic LBP (>6 months) and degenerative lumbar OA. INTERVENTIONS Daily intake of 1500 mg of oral glucosamine (n = 125) or placebo (n = 125) for 6 months, with assessment of effect after the 6-month intervention period and at 1 year (6 months postintervention). MAIN OUTCOME MEASURES The primary outcome was pain-related disability measured with the Roland Morris Disability Questionnaire (RMDQ). Secondary outcomes were numerical scores from pain-rating scales of patients at rest and during activity, and the quality-of-life EuroQol-5 Dimensions (EQ-5D) instrument. Data collection occurred during the intervention period at baseline, 6 weeks, 3 and 6 months, and again 6 months following the intervention at 1 year. Group differences were analyzed using linear mixed models analysis. RESULTS At baseline, mean RMDQ scores were 9.2 (95% confidence interval [CI], 8.4-10.0) for glucosamine and 9.7 (95% CI, 8.9-10.5) for the placebo group (P = .37). At 6 months, the mean RMDQ score was the same for the glucosamine and placebo groups (5.0; 95% CI, 4.2-5.8). At 1 year, the mean RMDQ scores were 4.8 (95% CI, 3.9-5.6) for glucosamine and 5.5 (95% CI, 4.7-6.4) for the placebo group. No statistically significant difference in change between groups was found when assessed after the 6-month intervention period and at 1 year: RMDQ (P = .72), LBP at rest (P = .91), LBP during activity (P = .97), and quality-of-life EQ-5D (P = .20). Mild adverse events were reported in 40 patients in the glucosamine group and 46 in the placebo group (P = .48). CONCLUSIONS Among patients with chronic LBP and degenerative lumbar OA, 6-month treatment with oral glucosamine compared with placebo did not result in reduced pain-related disability after the 6-month intervention and after 1-year follow-up. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00404079.

Acute effects of intramedullary reaming on bone blood flow in rats

We examined the acute effects of increasing degree of intramedullary reaming on bone blood flow in 27 male Wistar rats by use of the microsphere method. A marginal reduction in total bone and cortical bone blood flow was seen when the femoral canal was reamed to a diameter smaller than the medullary cavity (1.5 mm). Reaming equal to the antero-posterior diameter (1.8 mm) halved total bone flow and reduced cortical blood flow by one third. Reaming equal to the transverse diameter (2.1 mm) reduced total bone flow to one third and cortical bone flow by one third. Intramedullary reaming of the tibia to 1.5 mm reduced total blood flow about 50 percent whereas cortical flow in the proximal half was unchanged. We conclude that modest intramedullary reaming has little effect on total and cortical blood flows, whereas reaming which involves destruction of the endosteal cortex reduces both total bone and cortical blood flows.

Effects of instability on bone healing. Femoral osteotomies studied in rats.

Instability was induced in transversally osteotomized rat femora by means of intramedullary nails with various degrees of interlocking. Osteotomies that were stably pinned healed with less callus than those unstably pinned; no differences were found between rotational stable and unstable pinned osteotomies. Mechanical testing revealed that osteotomies treated by rotational stability and axial telescoping healed better than stably fixed and rotational unstable osteotomies. No differences were found between osteotomies treated by rotational instability and rigidily fixed fractures. We conclude that instability favors fracture healing as compared to rigidity. However, rotational instability in addition to telescoping impairs callus formation.

Restoration of bone flow following fracture and reaming in rat femora

In rats, bilateral closed femoral fracture was produced after intramedullary reaming to 1.6 mm on the left side and 2.0 mm on the right side. The fractures were fixed with 1.6 and 2.0 mm steel pins. Radioactive microspheres were used to determine bone blood flow at 30 min, 1 day, 3 days and 9 days after fracture. 8 rats were used to estimate normal bone blood flow, and an additional 8 rats to examine the vascular effects of fracture only. Following fracture, total bone blood flow was reduced to about 50 percent and cortical flow to about 40 percent of that in intact bones. Fracture and reaming to 1.6 mm reduced total bone flow to 40 percent and reaming to 2.0 mm reduced the total bone flow to approximately one third of normal flow. Cortical flow decreased to about one third and one quarter in the 2 groups. On Day 1, total flow was practically normalized in both groups. Cortical flow in the 1.6 mm group was about equal to that of intact bones, while it was about one third of normal flow in the 2.0-mm group, and significantly less than the 1.6-mm group. On Day 3, total bone flow was more than double that of intact bones and cortical flow 3 times greater in both groups. Flow continued to increase to Day 9 when a threefold increase in total bone blood flow and approximately a fivefold increase in cortical flow were found.(ABSTRACT TRUNCATED AT 250 WORDS)

Poor muscle coverage delays fracture healing in rats

We undertook this study in rats to ascertain the influence of muscle coverage on tibial fracture healing. 30 rats were randomly assigned to three intervention groups. Following a mid-diaphyseal osteotomy in the left tibia, reamed nailing was performed in all animals. In one group (A), the antero-lateral muscles were detached from the fractured bone, while the anterolateral compartment was excised in another group (B). In the third group (C), the muscle compartment was resected, and the superficial gluteal muscle was mobilized and transposed over the fractured area. Muscle intervention, like that in group A and C, had no effect on the blood flow. The fibular nerve was resected in all the rats. At 4 weeks, we studied the healing bones in each group clinically, radiologically and mechanically. At 4 weeks, radiographs in two planes revealed a clearly visible fracture line in the three experimental groups. Mechanical testing of the healing fractures showed significantly lower bending moment and bending rigidity in group B than in groups A and C. No difference in mechanical characteristics was detected between the healing bones in groups A and C. This animal study indicates that in tibial fractures, an extensive muscle tissue defect may have negative effects on early bone healing.

Effects of graded reaming on fracture healing: Blood flow and healing studied in rat femurs

In 30 rats, closed bilateral fractures of the femur were produced. On the left side intramedullary reaming was performed to 1.6 mm, and the fracture fixed-with a steel pin with a diameter of 1.6 mm. On the right side the femoral canal was reamed to 2.0 mm and a hollow steel tube with a diameter of 2.0 mm was used for fixation. An additional 8 rats were used to obtain mechanical, dimensional and flow data on intact femurs, and another 10 rats were used to study the acute flow changes caused by fracture and different degrees of reaming and fracture. Fracture and reaming reduced total bone and cortical bone blood flows to about one third of normal flow, with no differences between the 1.6-mm and the 2.0-mm reamed bones. At 4 weeks, total bone flow was about double and cortical bone flow about 4 times increased in the 1.6-mm group. In the 2.0-mm reamed bones increases of approximately 5 times in total bone flow and of about 7 times in cortical flow were found. Callus flow was about twice the size of the respective cortical flow in both groups. Both total and cortical flows gradually subsided, without differences between the 2 groups. At 12 weeks, the callus area in the 2.0-mm group was greater than in the 1.6-mm group, while bone dimensions were greater in the 2.0-mm group at 4 and 12 weeks. Bending moment and rigidity were greater in the 1.6-mm group than in the 2.0-mm one at every time interval; no differences were found in fracture energy.(ABSTRACT TRUNCATED AT 250 WORDS)