Matti Lehto

The effects of early mobilisation and immobilisation on the healing process following muscle injuries.

SummaryThe biological processes following muscle injury include 2 competitive events; regeneration of muscle fibres and the simultaneous production of granulation tissue. We have studied the effects of early mobilisation and immobilisation on the healing of rat gastrocnemius muscle fol-lowing partial rupture by a controlled contusion mechanism. Muscle fibre regeneration is inhibited by the formation of dense connective tissue scar. Immobilisation following injury limits the size of the connective tissue area formed within the site of injury; the penetration of muscle fibres through the connective tissue is prominent but their orientation is complex and not parallel with the uninjured muscle fibres. Immobilisation for longer than 1 week is followed by marked atrophy of the injured gastrocnemius muscle.Mobilisation started immediately after injury is followed by a dense scar formation in the injury area prohibiting muscle regeneration. When mobilisation is started after a short period of immobilisation a better penetration of muscle fibre through the connective tissue is found and the orientation of regenerated muscle fibres is aligned with the uninjured muscle fibres. Although a little delay in healing processes in muscles mobilised after short immobilisation was found morphologically, the gain in strength and energy absorption capacity was quite similar and as good as that of muscles treated by early mobilisation alone.

Quantitative alterations in intramuscular connective tissue following immobilization: an experimental study in the rat calf muscles.

The purpose of the present investigation was to study the effect of immobilization in two different positions, shortened or lengthened, on the connective tissue and capillarization of the rat calf muscles. In 18 rats the left hind limb was immobilized so that the soleus and gastrocnemius muscles were in a lengthened position and tibialis anterior was in a shortened position, and in 18 rats vice versa. The right hind limbs were kept free to serve as controls. After 1, 2, and 3 weeks of immobilization, an equal number of rats were killed and the muscles were analyzed. The connective tissue muscle ratio was measured from histological sections by automatic image analyzer and the number of capillaries per 1000 muscle fibers was also recorded. In the intact muscles the proportions of intramuscular connective tissue in the soleus, gastrocnemius, and tibialis anterior were 2, 3, and 5%, respectively. During the immobilization period of 3 weeks the proportion of connective tissue increased significantly in all muscles, but the only significant difference between the positions was in the soleus muscle in which more connective tissue was found in the lengthened position, 54% vs 30% in the shortened position. The amount of capillaries decreased significantly during immobilization in all muscles to about 65% of normal capillar density, but the position of immobilization seemed to have no effect on this phenomenon. The increase in intramuscular connective tissue during immobilization seems to occur simultaneously with muscle atrophy and loss of muscle capillarity. The stretched position of immobilization seems to have an additional fibrotic effect if the immobilized muscle, such as soleus, consists mainly of type I fibers generally known to be more vulnerable to disuse atrophy than type II fibers.

Endoneurial fibrosis following nerve transection

SummaryIndirect immunofluorescent techniques with antibodies to type I, III, and V collagens and fibronectin were used to study rat sciatic nerve tributaries after transection with intact contralateral nerves as controls.Codistribution of type I and III collagens characterized the epineurium of normal nerve. In the perineurium, however, type I collagen was absent, but type III and V collagens and fibronectin were detected. Type I and III collagens were codistributed in the endoneurial stroma where a homogeneous staining by antibodies to fibronectin was also observed.During the 4-week observation period after transection the perineurium reacted by slight thickening which was most clearly demonstrated by staining with antibodies to fibronectin and to type V collagen. A widening of the type I-negative cleft also occurred. Endoneurial, type V collagen-positive cuffs around the nerve fibers became disorganized, and a concomitant increase of the stroma containing type I and III collagens and fibronectin was observed.The codistribution of the fibrous collagen types appeared similar in normal epineurium and endoneurium. Type V collagen was locatd in the perineurium and in endoneurial cuffs surrounding the nerve fibers. The present data indicate that collagen accumulation takes place in the perineurium and endoneurium of transected nerve. The cell type responsible for the synthesis of the connective tissue material is discussed.

Development of peritoneal fibrosis occurs under the mesothelial cell layer.

This study was carried out in order to find out which part of the peritoneal wall reacts toward silica and produces peritoneal fibrosis. Colloidal silica was injected into the peritoneal cavity of rats to induce chemical peritonitis and frozen sections of the peritoneal wall were stained with specific antibodies toward type I and III collagens and fibronectin. A massive proliferation of granulation tissue was observed between the submesothelial and muscular layers within 48 hr visualized by prominent fibronectin staining. Type III collagen formed lamellar-like structures in the newly formed granulation tissue. The connective tissue reaction was extended into the underlying muscular tissue. Three weeks after silica injection the reactive granulation tissue exceeded the original peritoneum three- to fourfold in thickness. At this stage it contained extended fibrillar structures oriented perpendicular to the surface or muscular layers of the peritoneum. Type I collagen antibody was bound to the superficial cell layer in the control samples and in the early peritonitis whereas the entire granulation tissue was evenly stained at 3 weeks. Type III collagen antibody was bound to the surface layer of the peritoneum, granulation tissue, and perimysial connective tissue throughout the healing period. The results indicate that the peritoneal fibrotic process occurs under the thin peritoneal lining cell layer and on the surface of the muscle layer.

Is longer waiting time for total knee replacement associated with health outcomes and medication costs? Randomized clinical trial.

BACKGROUND The aim of this prospective randomized study was to evaluate the effect of waiting time (WT) on health-related quality of life (HRQoL), knee pain and physical function, and the use and costs of medication of patients awaiting total knee replacement. METHODS When placed on the waiting list, 438 patients were randomized into a short waiting time (SWT ≤ 3 months) or a nonfixed waiting time (NFWT > 3 months) group. HRQoL was measured by the 15D, and pain and physical function by modified Knee Society Clinical Rating System at baseline, admission, and 3 and 12 months postoperatively. The costs of medication due to osteoarthritis were calculated at the same measurement points. All analyses were performed using the intention-to-treat principle. RESULTS The mean WT was 94 and 239 days in the SWT and NFWT groups, respectively. Apart from higher weekly cost of medication in the SWT group at admission and better HRQoL in the NFWT group 1 year postoperatively, there were no statistically significant differences between the groups in other outcomes during the follow-up. CONCLUSION Those in the SWT group had higher weekly costs of medication at admission, and reached better HRQoL 3 months earlier than those in the NFWT group, but the latter had better HRQoL after operation. Otherwise, the length of WT was not associated with different health and HRQoL outcomes in the groups.

The Effect of Waiting Time on Health‐Related Quality of Life, Pain, and Physical Function in Patients Awaiting Primary Total Hip Replacement: A Randomized Controlled Trial

OBJECTIVE This prospective randomized study assessed the effect of waiting time (WT) on health outcomes in Finnish patients admitted to hospital for primary total hip replacement (THR). METHODS A total of 395 consecutive patients with a need for a primary THR because of osteoarthritis and who were placed on the waiting list between August 2002 and November 2003. After placement on the waiting list, the patients were randomly assigned to a short WT (<or=3 months) group (n = 174) or a nonfixed WT group (n = 221). The patients completed self-administered questionnaires at the time of placing on the waiting list and at hospital admission. Health-related quality of life was measured by the generic 15D instrument. Hip pain and function were measured by the patient self-report Harris hip score (HHS). RESULTS Of the 395 patients, 312 (79%) completed the follow-up (140 patients with short and 172 with nonfixed WT). At admission, the mean 15D scores for patients with short and nonfixed WT were 0.784 and 0.783, respectively. In the intention-to-treatment analysis, the difference between the groups (Delta 0.001, 95% confidence interval [CI]: -0.019 to 0.021) was not statistically significant or clinically important. The mean self-report HHS in patients with short WT was 43.5, and among those with nonfixed WT was 41.9. The difference (Delta 1.6, 95% CI: -1.77 to 4.87) was not statistically significant. CONCLUSIONS Both generic and disease-specific measures revealed that longer WTs did not result in poorer health status at admission.

The effect of waiting time on health and quality of life outcomes and costs of medication in hip replacement patients: a randomized clinical trial

OBJECTIVE To evaluate the effect of waiting time on health and quality of life outcomes and costs of medication in total hip replacement (THR) patients in a randomized clinical trial. METHODS 395 THR patients were recruited into the study. When placed on the waiting list, patients were randomized into a short (< or =3 months) or a non-fixed waiting time (NFWT) (>3 months) group. In the final analyses 309 patients (179 women) with a mean age of 65 years were included. Health-related quality of life (HRQoL) (generic 15D), and pain and function (modified Harris Hip Score (HHS)) were calculated when placed on the waiting list, at hospital admission, and at 3 and 12 months postoperatively. The costs of disease-specific medication were calculated at the same measurement points. All analyses were performed using the intention-to-treat (ITT) principal. RESULTS Of the recruited patients, 309 (78%) completed the follow-up (short group 140 and non-fixed group 169 patients). The mean waiting time was 74 days in the short and 194 days in the NFWT groups. In the ITT analyses there were no statistically significant differences between the groups in the weekly use and costs of medication, HRQoL or HHS at baseline, at admission, or 3 or 12 months after surgery. The only difference was in total medication costs during the waiting time period, at EUR 83 and 171, respectively. CONCLUSIONS The length of the waiting time did not generate different effects on the studied health and quality of life outcomes of the randomized groups. However, those in short waiting time group reached earlier better HRQoL.