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Dive into the research topics where Per Hamberg is active.

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Featured researches published by Per Hamberg.


Journal of Bone and Joint Surgery, American Volume | 1983

Suture of new and old peripheral meniscus tears.

Per Hamberg; Jan Gillquist; J Lysholm

A prospective study of repaired vertical peripheral tears of the meniscus in fifty patients (nine women and forty-one men) was carried out from January 1977 to June 1980. All tears were confirmed preoperatively by arthroscopy. Forty-three medial and seven lateral menisci were repaired. Fifteen tears were treated within two weeks and thirty-five were operated on as long as seven years after injury. Only eight patients had a meniscal tear that was not accompanied by injuries of either the anterior cruciate ligament or the collateral ligaments, or both. At a mean follow-up of eighteen months (range, six to thirty-nine months), forty-two patients (84 per cent) had clinically apparent healing of the sutured meniscal tear. Repeat arthroscopy was done in twenty-seven (64 per cent) of these patients, four to twenty-nine months (mean, twelve months) after the operation. The arthroscopy proved that all of these repaired tears had healed. Eight patients had a second tear after the initial repair: four were reruptures at the sutured area and four were new ruptures in another area of the meniscus and were associated with fresh trauma. All of these patients subsequently had an arthroscopic meniscectomy.


Arthroscopy | 2001

Semitendinosus Muscle in Anterior Cruciate Ligament Surgery: Morphology and Function

Karl Eriksson; Per Hamberg; Eva Jansson; Hans Larsson; Adel Shalabi; Torsten Wredmark

PURPOSE To evaluate the fate of the hamstring muscles in general and the semitendinosus muscle in particular, after anterior cruciate ligament (ACL) reconstruction with an autologous semitendinosus tendon graft from the ipsilateral side. TYPE OF STUDY Prospective consecutive case series investigation. METHODS Included were 16 consecutive patients, 14 male and 2 female, with a mean age of 26 years. The inclusion criterion was chronic unilateral ACL insufficiency with no concomitant knee ligament injuries. ACL reconstruction was performed with a quadruple semitendinosus tendon graft using the EndoButton technique (Acufex, Mansfield, MA). Intraoperatively, muscle specimens were taken from the semitendinosus muscle on the harvested side. Follow-up at a minimum of 6 months included clinical examination, isokinetic strength performance, magnetic resonance imaging (MRI) of the thigh and knee, and ultrasound-guided muscle biopsy procurement from the semitendinosus muscle for histochemical and enzymatic analyses. RESULTS Of the patients, 75% showed regeneration of their semitendinosus tendons. The neotendons all inserted below the knee joint where they had fused with the gracilis tendon to a conjoined tendon inserting in the pes anserinus. The semitendinosus muscle had a smaller cross-sectional area on the operated side but none showed total atrophy. Less atrophy was present in the patients with a regenerated semitendinosus neotendon compared with those without regeneration (P =.029). In the latter group the semimembranosus muscle seemed to compensate for this with hypertrophy (P =.019). Cross-sectional muscle fiber areas, the relative number of each fiber type and oxidative potential as estimated by citrate synthase activity, showed no significant differences between the operated and nonoperated legs. The isokinetic strength of the hamstrings and quadriceps was significantly lower in the operated leg than in the nonoperated leg. CONCLUSIONS With this surgical technique, the semitendinosus muscle can recover and the tendon has, according to the MRI images, a great potential to regenerate after its removal.


Arthroscopy | 1987

The correlation between osteoarthrosis as seen on radiographs and on arthroscopy

Jack Lysholm; Per Hamberg; Jan Gillquist

The correlation between arthroscopic and radiographic osteoarthrosis was studied in 63 patients (51 +/- 12 years) with degenerative changes in the medial compartment of the knee involving the medial meniscus with or without chondral damage. Chondral damage on arthroscopy was classified in grades 1-3 modified after Outerbridge. The radiographic evaluation was done according to Ahlbäck classification. Twenty-eight patients (44%) did not show any significant chondral damage on arthroscopy (grades 0-1). The radiographic findings in this group were usually normal. Three patients, however, showed a slight narrowing of the medial joint space (Ahlbäck I). All three had severely degenerated menisci, and two of them showed superficial fibrillation of both the tibia and the femur. Twenty-four patients (38%) showed a partial thickness chondral damage with fragmentation of the surface (grade 2). Radiographic findings were usually normal; however, patients with involvement of both the tibia and the femur often showed a joint space narrowing on radiographs. Eleven patients (18%) showed destruction of the cartilage down to subchondral bone (grade 3). The typical radiographic finding was a joint space obliteration (Ahlbäck II). Involvement also of the lateral compartment as assessed on arthroscopy was significantly more common in patients with 2nd and 3rd degree chondral disease and Ahlbäck II and III on radiographs than in those with 2nd and 3rd degree chondral damage and normal radiographs. In all but one of the patients with involvement of both compartments, the lateral compartment was considered normal on radiographic examination.


Knee Surgery, Sports Traumatology, Arthroscopy | 2001

Semitendinosus tendon regeneration after harvesting for ACL reconstruction. A prospective MRI study.

Karl Eriksson; Hans Larsson; Torsten Wredmark; Per Hamberg

Abstract Utilisation of the semitendinosus and gracilis tendons in reconstruction of the anterior cruciate ligament (ACL) has become more common during the last few years. In recent studies a regeneration potential in the harvested tendons has been observed. In this study, 11 consecutive patients who underwent ACL reconstruction with a quadruple semitendinosus graft were examined 6–12 months postoperatively by MRI. Another two patients were examined within 2 weeks after surgery. The median age of the patients was 24 years and there were 8 males and 3 females. The right knee was involved in six patients and the left knee in five. A low-field 0.2 Tesla Siemens open MRI was used for examinations and T1 and T2 weighted transaxial sequences over the thigh and the knee joint were performed. In some instances, additional sagittal sequences were used. ROI analysis of the pixel value of the signal and area determinations on transaxial sequences was performed for both the involved and the healthy side. In 8 of the 11 patients examined 6–12 months postoperatively, a regeneration of the semitendinosus tendon with normal anatomical topographies to the level of the tibial plateau was found. Three of these eight patients were analysed more distally and fusion of the semitendinosus and gracilis tendons was found approximately 30 mm below the joint line before they inserted as a “conjoined tendon” into the pes anserinus. At the mid-thigh level, the semitendinosus muscle had a smaller area and a higher signal than that on the normal side. However, this difference was smaller in the patients showing normal distal tendon regeneration. This study indicates that the semitendinosus tendon has a strong potential for regeneration and that the muscle atrophy seems to be less in the patients with a more normalised distal insertion of the tendon in the pes anserinus.


Journal of Pediatric Orthopaedics | 1984

Arthroscopy of the knee in children.

Richard Bergström; Jan Gillquist; Jack Lysholm; Per Hamberg

A review was carried out of arthroscopy of the knee in children. During a 34-month period, 2,378 arthroscopies were performed, 80 of these on children less than 16 years of age. Seventy-one cases were reviewed, which is approximately 2% of all children seen at the clinic. Thirty procedures were carried out in patients with hemarthrosis. Eleven patients required operative repair or reconstruction. There were 13 ruptures of the anterior cruciate ligament (43%), 4 ruptures of the posterior cruciate ligament, 14 ruptures of the medial collateral or posterior oblique ligament, and 5 ruptures of the lateral meniscus. Forty-one arthroscopies were done in patients without hemarthrosis or history of acute trauma. A clinical diagnosis of meniscus tear was correct in only 20%. Only one meniscectomy was performed and another meniscus tear was repaired. The most common diagnostic finding was abnormality of the patellofemoral articulation, which was diagnosed in 31 patients. Arthroscopic shaving of the patella was rarely indicated. As in adults, hemarthrosis indicates significant injury to the knee. Meniscus lesions are rare.


Acta Orthopaedica Scandinavica | 2001

The semitendinosus tendon regenerates after resection: A morphologic and MRI analysis in 6 patients after resection for anterior cruciate ligament reconstruction

Karl Eriksson; Lars Gunnar Kindblom; Per Hamberg; Hans Larsson; Torsten Wredmark

Recently, the surprising observation has been made, supported by clinical and MRI findings, that the semitendinosus tendon can regenerate after being harvested in its whole length and thickness for anterior cruciate ligament reconstruction. We studied 6 patients with previous anterior cruciate ligament reconstruction, using a quadruple semitendinosus tendon autograft. In 5 of these, physical examination and MRI showed that the tendond had regenerated. In all 6 patients, the findings were documented macroscopically by open surgical exploration and in the 5 regenerated tendons, also morphologically by biopsies. Macroscopically, histologically and immunohistochemically the regenerated tendons closely resembled normal ones with focal scar-like areas. Our present findings and earlier studies show that full length and thickness harvesting of the semitendinosus tendon in most cases result in full-length tendon regeneration with tissue closely resembling the normal tendon.


Scandinavian Journal of Medicine & Science in Sports | 2001

There are differences in early morbidity after ACL reconstruction when comparing patellar tendon and semitendinosus tendon graft

Karl Eriksson; P. Anderberg; Per Hamberg; P. Olerud; Torsten Wredmark

The main objective of this study was to study solely early postoperative morbidity following anterior cruciate ligament (ACL) reconstruction by comparing the gold standard procedure, the bone‐patellar tendon‐bone graft (BTB), and one of the most common alternatives, the semitendinosus tendon graft (ST). The prospective study included 107 randomized patients (50 BTB and 57 ST). The follow‐up period was set to 20–35 weeks postoperatively (mean 26.8±3.5 weeks). One patient suffered early graft rupture and 89 (84%) of the remaining 106 patients were able to attend the follow‐up within the given time limit. There were no differences in sick leave between the groups. The Lysholm score, Tegner activity level score and Visual Analog Scales (VAS) with the questions “How does your knee function?” and “How does your knee affect your activity level?” revealed no differences between the groups. Subjective patellofemoral pain, patellofemoral compartment findings and donor site morbidity were more common in the BTB group, P<0.05. Lachman test grade 1+ was more common in the ST group, P<0.05, but there was no significant difference in instrumented Lachman side‐to‐side comparison. The ST group scored better in the one‐leg hop test than the BTB group, P<0.05. No correlations between these clinical and functional findings and subjective knee function scores were found. In conclusion, ACL reconstruction with ST tendon graft presented fewer short‐term postoperative problems as compared to reconstruction with BTB.


Journal of Bone and Joint Surgery, American Volume | 2012

Lower Tourniquet Cuff Pressure Reduces Postoperative Wound Complications After Total Knee Arthroplasty A Randomized Controlled Study of 164 Patients

Charlotta Olivecrona; Sari Ponzer; Per Hamberg; Richard Blomfeldt

BACKGROUND Measurement of limb occlusion pressure before surgery might lead to the use of a lower tourniquet cuff pressure during surgery and thereby reduce the risk of postoperative pain and complications. The primary aim of this study was to investigate whether the limb-occlusion-pressure method reduces the tourniquet cuff pressure used during total knee arthroplasty and if this leads to less postoperative pain compared with that experienced by patients on whom this method is not used. The secondary aim was to investigate whether there were any differences regarding the quality of the bloodless field, range of motion, and postoperative wound complications. METHODS One hundred and sixty-four patients scheduled to be treated with a total knee arthroplasty were randomized to a control group or to undergo the intervention under study (the limb-occlusion-pressure [LOP] group). In the control group, the tourniquet cuff pressure was based on the patients systolic blood pressure and a margin decided by the surgeon (the routine method). In the LOP group, the tourniquet cuff pressure was based on the measurement of the limb occlusion pressure. The primary outcome measure was postoperative pain, and the secondary outcome measures were the quality of the bloodless field, knee motion, and wound-related complications at discharge and two months after surgery. RESULTS The tourniquet cuff pressure was significantly lower in the LOP group than in the control group (p < 0.001). We could not demonstrate any differences between the groups regarding postoperative pain or complications, although the number of postoperative complications was relatively high in both groups. However, at discharge forty of the forty-seven patients with a wound complication had had a cuff pressure above 225 mm Hg and at the two-month follow-up evaluation fourteen of the sixteen patients with a wound complication had had a cuff pressure above 225 mm Hg. CONCLUSIONS The limb-occlusion-pressure method reduces the cuff pressure without reducing the quality of the bloodless field, but there were no differences in outcomes between the groups. An important secondary finding was that patients with a cuff pressure of ≤225 mm Hg had no postoperative infections and a lower rate of wound complications.


Acta Orthopaedica Scandinavica | 1984

Knee function after arthroscopic meniscectomy: A prospective study

Per Hamberg; Jan Gillquist

In a prospective study, operation under arthroscopy was done in 100 consecutive patients (11 women and 89 men) with a lesion of one meniscus. Meniscectomy was done in 86 patients with medial meniscus tears and in 14 with lateral tears. After 2 weeks, 85 patients were back at work.


Acta Orthopaedica | 2006

Skin protection underneath the pneumatic tourniquet during total knee arthroplasty A randomized controlled trial of 92 patients

Charlotta Olivecrona; Jan Tidermark; Per Hamberg; Sari Ponzer; Claes Cederfjäll

Background The use of a pneumatic tourniquet to obtain a bloodless field during a total knee arthroplasty (TKA) allows the surgeon to work with greater technical precision in a safe, clear environment. Despite the benefits of surgical tourniquets and many advances in tourniquet equipment, their use is not without risk and complications may still occur. The primary aim of this study was to determine whether there are any differences between an elastic stockinette, cast padding, and no protective material at all regarding skin injuries after a primary TKA in a bloodless field using a pneumatic tourniquet. Methods 92 patients were randomized to 1 of 3 groups. In the first group, the limb underneath the pneumatic tourniquet was protected by a two-layer elastic stockinette (E). In the second group, it was protected by cast padding (C), and no protective material (N) was used in the third group. The presence of major skin injuries (blisters) was recorded when the tourniquet was removed after surgery. Results The two groups with skin protection had fewer skin injuries (p = 0.007). The elastic stockinette was significantly better than having no protective material and there was a trend towards better results in the elastic stockinette group than in the cast padding group. Interpretations Our findings indicate that protective material underneath the tourniquet cuff reduces the risk of skin injuries, i.e. blisters. An elastic stockinette appears to be best.

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Torsten Wredmark

Karolinska University Hospital

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Eva Jansson

Karolinska University Hospital

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