To investigate the result of cemented revision hip arthroplasty. Twenty-one revision hip arthropl... more To investigate the result of cemented revision hip arthroplasty. Twenty-one revision hip arthroplasties for aseptic loosening with cementing technique during the period 1990-2002 were followed-up. There were 12 women and 9 men with mean age at the time of revision 61 years (33 to 76 years). The mean follow-up for the group was 5.2 years (range, 2 to 13 years). The clinical evaluation was performed with the Harris hip score. Implant survival, pain, function and complications were recorded. Plain radiographs were reviewed and the hips were graded for osteolysis and loosening. Wear of the polyethylene was measured. No component was exchanged. Three of the acetabular and three of the stem components in the hips with early cementing technique were loose. In two patients three surgeries were performed for trochanteric problems and persistent pain. Clinical result and bone defects preoperatively as well as wear and osteolysis correlated significantly. Stable fixation of the prosthesis is o...
To investigate the result of cemented revision hip arthroplasty. Twenty-one revision hip arthropl... more To investigate the result of cemented revision hip arthroplasty. Twenty-one revision hip arthroplasties for aseptic loosening with cementing technique during the period 1990-2002 were followed-up. There were 12 women and 9 men with mean age at the time of revision 61 years (33 to 76 years). The mean follow-up for the group was 5.2 years (range, 2 to 13 years). The clinical evaluation was performed with the Harris hip score. Implant survival, pain, function and complications were recorded. Plain radiographs were reviewed and the hips were graded for osteolysis and loosening. Wear of the polyethylene was measured. No component was exchanged. Three of the acetabular and three of the stem components in the hips with early cementing technique were loose. In two patients three surgeries were performed for trochanteric problems and persistent pain. Clinical result and bone defects preoperatively as well as wear and osteolysis correlated significantly. Stable fixation of the prosthesis is o...
During routine anatomical dissections two cases of unusually structured abductor digiti minimi mu... more During routine anatomical dissections two cases of unusually structured abductor digiti minimi muscle were discovered. In the first case, the variant muscle body was composed of three well-defined portions: lateral, intermediate and medial. The three portions fused in a common muscular body that attached to the ulnar side of the base of the fifth proximal phalanx. In the second case, the aberrant muscle was composed of two portions: lateral and medial. Distally, they fused in a common muscular body that distally inserted as in previous case. Because in each one of the cases a portion from the aberrant muscle crossed over the ulnar nerve and artery in the Guyon’s canal, both variant abductor digiti minimi muscles could be of clinical interest in differential diagnosis of ulnar nerve entrapment.
Purpose: Periprosthetic fractures are one of the most serious complications after hip replacement... more Purpose: Periprosthetic fractures are one of the most serious complications after hip replacement. 30
Thigh pain has been consistently reported with cementless hip arthroplasty. The correlation betwe... more Thigh pain has been consistently reported with cementless hip arthroplasty. The correlation between thigh pain and radiological findings and the clinical significance of thigh pain have not been studied in any detail. We carried out a retrospective study to analyse the performance of a proximally porous-coated cementless femoral component. Ninety-eight total hip arthroplasties were followed up clinically and radiologically for an average of 33 months (range: 12 to 64) after operation. The clinical results were good or excellent in 85 cases (87%). Thirteen patients (13%) reported thigh pain at latest follow-up. Subsidence of the stem was recorded in 10 cases, cortical thickening occurred in 14 hips (14%), and 17 hips (17%) presented proximal osteopenia. Proximally, radiolucent lines were observed in 11 cases. Thigh pain correlated with radiolucent lines, femoral thickening, fibrous fixation and stem migration. Bone remodelling was noted to continue even five years after implantation....
Aseptic loosening due to bone remodeling and osteolysis is the main reason for revision hip arthr... more Aseptic loosening due to bone remodeling and osteolysis is the main reason for revision hip arthroplasty. At present, there is no established prophylaxis for this complication. On the other hand, it has been demonstrated that bisphosphonates prevent bone loss around total hip arthroplasties (THA). The aim of this study was to assess the efficacy of oral bisphosphonate risedronate for the prevention of deleterious changes in bone metabolism after hip replacement. Twenty-four patients who underwent THA were randomised to two treatment arms: 35 mg risedronate once weekly for 6 months (12 patients) and no treatment for controls (12 patients). Markers of bone turnover bone specific alkaline phosphatase, serum osteocalcin and urinary deoxypiridinoline were evaluated at baseline, third and sixth postoperative month. Dual energy X-ray absorptiometry of the nonsurgical hip was performed preoperatively and at 6 months postoperatively. There were no significant differences in clinical or radio...
This article describes the surgical technique for total hip arthroplasty using the single-incisio... more This article describes the surgical technique for total hip arthroplasty using the single-incision direct anterior approach. The authors believe the direct anterior approach has significant advantages, including minimal soft tissue trauma, resulting in faster postoperative mobilization and rehabilitation. The small incision scar also results in better cosmesis.
The goal of this study was to compare the kinematics of knees before and after total knee arthrop... more The goal of this study was to compare the kinematics of knees before and after total knee arthroplasty (TKA) that relies on an inter-condylar 'third condyle'. The hypothesis was that the 'third condyle' provides sufficient flexion stability and induces a close to normal femoral rollback, thus granting natural joint kinematics. Intra-operative navigation data were collected from 29 consecutive cases that received a cemented TKA (HLS Noetos, Tornier SA, France) designed with an inter-condylar 'third condyle' that engages within the tibial insert beyond 35° flexion. Operations were guided by a non-image-based system (BLU-IGS, Orthokey Italia srl, Italy) that recorded relative femoral and tibial positions in native and implanted knees during: passive range of motion, anterior drawer test at 90° flexion, and varus-valgus stress tests at full extension and at 30° flexion. The total internal tibial rotation during flexion was similar for native (8.2 ± 4.2°) and implanted knees (8.0 ± 5.4°). The lateral femoral condyle was more posterior in implanted knees (1.2 ± 9.4 mm) than in…
Fibrous pseudocapsule around hip implants is an invariable finding at revision operations and is ... more Fibrous pseudocapsule around hip implants is an invariable finding at revision operations and is believed to release inflammatory mediators that stimulate bone resorption. Reactive oxygen species have been proposed to be causative factors in various disorders with tissue fibrosis. We were interested in investigating whether aseptic loosening is connected with high oxidative stress, and in showing the underlying mechanism of periprosthetic fibrosis and its role in loosening. Levels of oxidative stress markers reduced (GSH) and oxidized (GSSG) gluthatione and malondialdehyde (MDA) were assayed in 28 loose hips and in 12 stable hips revised for high rate of wear and osteolysis. Collagen in the periprosthetic tissues was measured as hydroxyproline content. Osteolysis and polyethylene wear were graded. Increased oxidative stress measured by low GSH/ GSSG ratio as well as by increased MDA level was established in patients compared to controls. Oxidative stress markers intercorrelated significantly. MDA and both GSH and GSSG levels correlated significantly with hydroxyproline level. Levels of GSSG and MDA were higher in hips with greater polyethylene wear. The results suggest that high oxidative stress may play a role in formation of a fibrous membrane observed at revision of loose hips. The fibrous pseudocapsule is probably related to high intraarticular pressure and expansion of the effective joint space. This study may elicit some aspects of the pathogenesis of aseptic hip loosening and aid in future investigations aiming at prevention of this complication. ß
The reparation and the distribution of fibrillar collagens in the lateral collateral ligament epi... more The reparation and the distribution of fibrillar collagens in the lateral collateral ligament epiligament tissue may have an important role during early healing. The aim of this study was to determine the different types of fibrillar collagens synthesized in the epiligament scar throughout the initial thirty days after injury in rats. Therefore, we performed surgical transection of this ligament using rat knee model and allowed the tissue to heal spontaneously. On the eighth, sixteenth and thirtieth day after injury, the animals were sacrificed and the ligaments were examined. Our results revealed that on the eighth and sixteenth day post-injury the epiligament tissue was not completely regenerated. Immunohistochemical studies revealed localization of type I, III and V collagen in the EL substance. On the thirtieth day after injury the epiligament was similar to normal, but not fully restored. Immunohistochemical reactions for collagens type I, III and V were also positive. This study presents detailed description of the early epiligament healing process and illustrates for the first time the distribution of fibrillar collagens during epiligament healing.
Bisphosphonates are the most widely prescribed treatment for postmenopausal osteoporosis, seconda... more Bisphosphonates are the most widely prescribed treatment for postmenopausal osteoporosis, secondary osteoporosis, and male osteoporosis. Notwithstanding their high effectiveness and favorable safety profile, the adherence to bisphosphonate treatment remains low. Different treatment strategies aim to improve the clinical effectiveness of bisphosphonate therapy. This review paper assesses the clinical utility of oral intermittent risedronate in the treatment of postmenopausal osteoporosis. The new delayed-release risedronate formulation is a safer and easy to use alternative to other risedronate therapy. Oral risedronate, a potent nitrogen-containing bisphosphonate, has been extensively studied using daily regimens. A new intermittent (weekly) dosing regimen confirmed its clinical effectiveness in relation to vertebral and nonvertebral fracture prevention. The absence of significant differences in the incidence of adverse effects confirmed the favorable tolerability of the weekly dosage. In efforts to improve patient adherence to treatment, an innovative, delayed-release formulation of risedronate, which ensures adequate bioavailability of the active compound when taken with food, was introduced. The once-weekly delayed-release formulation of risedronate proved to be noninferior to the daily dosage of risedronate in terms of bone mineral density and markers of bone turnover. In addition, the incidence of new morphometric vertebral fractures was comparable in both treatment regimens. The new delayed-release formulation of risedronate showed a favorable safety profile. Delayed-release risedronate is a promising, new, effective, and convenient alternative to current bisphosphonate treatments. It appears to allow better patient adherence to antiresorptive treatment.
Background: In this study, we evaluated the changes which occurred in the epiligament, an envelop... more Background: In this study, we evaluated the changes which occurred in the epiligament, an enveloping tissue of the ligament, during the ligament healing. We assessed the association of epiligament elements that could be involved in ligament healing. Methods: Thirty-two 8-month old male Wistar rats were used in this study. In twenty-four of them the lateral collateral ligament of the knee joint was surgically transected and was allowed to heal spontaneously. The evaluation of the epiligament healing included light microscopy and transmission electron microscopy. Results: At the eight, sixteenth and thirtieth day after injury, the animals were sacrificed and the ligaments were examined. Our results revealed that on the eight and sixteenth day post-injury the epiligament tissue is not completely regenerated. Till the thirtieth day after injury the epiligament is similar to normal, but not fully restored. Conclusion: Our study offered a more complete description of the epiligament healing process and defined its important role in ligament healing. Thus, we provided a base for new strategies in ligament treatment.
During routine anatomical dissection a rare case of a flexor digitorum accessorius longus muscle ... more During routine anatomical dissection a rare case of a flexor digitorum accessorius longus muscle was observed. This muscle arose with a well-formed muscular belly from the lower part of the lateral intermuscular septum, and then passed obliquely downward and medially deep to the calcanean tendon in the canal of the flexor hallucis longus. In the sole region the aberrant muscle prolonged in a thin tendon that divided into two parts: superficial and deep. The superficial part attached to the tendon of the flexor digitorum longus for the second toe; the deep part of the tendon joined the tendon of the quadratus plantae and also an additional portion of the flexor hallucis longus tendon to the second toe. The possible clinical implications of this muscle in practical surgery and also in imaging radiology are reviewed.
To investigate the result of cemented revision hip arthroplasty. Twenty-one revision hip arthropl... more To investigate the result of cemented revision hip arthroplasty. Twenty-one revision hip arthroplasties for aseptic loosening with cementing technique during the period 1990-2002 were followed-up. There were 12 women and 9 men with mean age at the time of revision 61 years (33 to 76 years). The mean follow-up for the group was 5.2 years (range, 2 to 13 years). The clinical evaluation was performed with the Harris hip score. Implant survival, pain, function and complications were recorded. Plain radiographs were reviewed and the hips were graded for osteolysis and loosening. Wear of the polyethylene was measured. No component was exchanged. Three of the acetabular and three of the stem components in the hips with early cementing technique were loose. In two patients three surgeries were performed for trochanteric problems and persistent pain. Clinical result and bone defects preoperatively as well as wear and osteolysis correlated significantly. Stable fixation of the prosthesis is o...
To investigate the result of cemented revision hip arthroplasty. Twenty-one revision hip arthropl... more To investigate the result of cemented revision hip arthroplasty. Twenty-one revision hip arthroplasties for aseptic loosening with cementing technique during the period 1990-2002 were followed-up. There were 12 women and 9 men with mean age at the time of revision 61 years (33 to 76 years). The mean follow-up for the group was 5.2 years (range, 2 to 13 years). The clinical evaluation was performed with the Harris hip score. Implant survival, pain, function and complications were recorded. Plain radiographs were reviewed and the hips were graded for osteolysis and loosening. Wear of the polyethylene was measured. No component was exchanged. Three of the acetabular and three of the stem components in the hips with early cementing technique were loose. In two patients three surgeries were performed for trochanteric problems and persistent pain. Clinical result and bone defects preoperatively as well as wear and osteolysis correlated significantly. Stable fixation of the prosthesis is o...
During routine anatomical dissections two cases of unusually structured abductor digiti minimi mu... more During routine anatomical dissections two cases of unusually structured abductor digiti minimi muscle were discovered. In the first case, the variant muscle body was composed of three well-defined portions: lateral, intermediate and medial. The three portions fused in a common muscular body that attached to the ulnar side of the base of the fifth proximal phalanx. In the second case, the aberrant muscle was composed of two portions: lateral and medial. Distally, they fused in a common muscular body that distally inserted as in previous case. Because in each one of the cases a portion from the aberrant muscle crossed over the ulnar nerve and artery in the Guyon’s canal, both variant abductor digiti minimi muscles could be of clinical interest in differential diagnosis of ulnar nerve entrapment.
Purpose: Periprosthetic fractures are one of the most serious complications after hip replacement... more Purpose: Periprosthetic fractures are one of the most serious complications after hip replacement. 30
Thigh pain has been consistently reported with cementless hip arthroplasty. The correlation betwe... more Thigh pain has been consistently reported with cementless hip arthroplasty. The correlation between thigh pain and radiological findings and the clinical significance of thigh pain have not been studied in any detail. We carried out a retrospective study to analyse the performance of a proximally porous-coated cementless femoral component. Ninety-eight total hip arthroplasties were followed up clinically and radiologically for an average of 33 months (range: 12 to 64) after operation. The clinical results were good or excellent in 85 cases (87%). Thirteen patients (13%) reported thigh pain at latest follow-up. Subsidence of the stem was recorded in 10 cases, cortical thickening occurred in 14 hips (14%), and 17 hips (17%) presented proximal osteopenia. Proximally, radiolucent lines were observed in 11 cases. Thigh pain correlated with radiolucent lines, femoral thickening, fibrous fixation and stem migration. Bone remodelling was noted to continue even five years after implantation....
Aseptic loosening due to bone remodeling and osteolysis is the main reason for revision hip arthr... more Aseptic loosening due to bone remodeling and osteolysis is the main reason for revision hip arthroplasty. At present, there is no established prophylaxis for this complication. On the other hand, it has been demonstrated that bisphosphonates prevent bone loss around total hip arthroplasties (THA). The aim of this study was to assess the efficacy of oral bisphosphonate risedronate for the prevention of deleterious changes in bone metabolism after hip replacement. Twenty-four patients who underwent THA were randomised to two treatment arms: 35 mg risedronate once weekly for 6 months (12 patients) and no treatment for controls (12 patients). Markers of bone turnover bone specific alkaline phosphatase, serum osteocalcin and urinary deoxypiridinoline were evaluated at baseline, third and sixth postoperative month. Dual energy X-ray absorptiometry of the nonsurgical hip was performed preoperatively and at 6 months postoperatively. There were no significant differences in clinical or radio...
This article describes the surgical technique for total hip arthroplasty using the single-incisio... more This article describes the surgical technique for total hip arthroplasty using the single-incision direct anterior approach. The authors believe the direct anterior approach has significant advantages, including minimal soft tissue trauma, resulting in faster postoperative mobilization and rehabilitation. The small incision scar also results in better cosmesis.
The goal of this study was to compare the kinematics of knees before and after total knee arthrop... more The goal of this study was to compare the kinematics of knees before and after total knee arthroplasty (TKA) that relies on an inter-condylar 'third condyle'. The hypothesis was that the 'third condyle' provides sufficient flexion stability and induces a close to normal femoral rollback, thus granting natural joint kinematics. Intra-operative navigation data were collected from 29 consecutive cases that received a cemented TKA (HLS Noetos, Tornier SA, France) designed with an inter-condylar 'third condyle' that engages within the tibial insert beyond 35° flexion. Operations were guided by a non-image-based system (BLU-IGS, Orthokey Italia srl, Italy) that recorded relative femoral and tibial positions in native and implanted knees during: passive range of motion, anterior drawer test at 90° flexion, and varus-valgus stress tests at full extension and at 30° flexion. The total internal tibial rotation during flexion was similar for native (8.2 ± 4.2°) and implanted knees (8.0 ± 5.4°). The lateral femoral condyle was more posterior in implanted knees (1.2 ± 9.4 mm) than in…
Fibrous pseudocapsule around hip implants is an invariable finding at revision operations and is ... more Fibrous pseudocapsule around hip implants is an invariable finding at revision operations and is believed to release inflammatory mediators that stimulate bone resorption. Reactive oxygen species have been proposed to be causative factors in various disorders with tissue fibrosis. We were interested in investigating whether aseptic loosening is connected with high oxidative stress, and in showing the underlying mechanism of periprosthetic fibrosis and its role in loosening. Levels of oxidative stress markers reduced (GSH) and oxidized (GSSG) gluthatione and malondialdehyde (MDA) were assayed in 28 loose hips and in 12 stable hips revised for high rate of wear and osteolysis. Collagen in the periprosthetic tissues was measured as hydroxyproline content. Osteolysis and polyethylene wear were graded. Increased oxidative stress measured by low GSH/ GSSG ratio as well as by increased MDA level was established in patients compared to controls. Oxidative stress markers intercorrelated significantly. MDA and both GSH and GSSG levels correlated significantly with hydroxyproline level. Levels of GSSG and MDA were higher in hips with greater polyethylene wear. The results suggest that high oxidative stress may play a role in formation of a fibrous membrane observed at revision of loose hips. The fibrous pseudocapsule is probably related to high intraarticular pressure and expansion of the effective joint space. This study may elicit some aspects of the pathogenesis of aseptic hip loosening and aid in future investigations aiming at prevention of this complication. ß
The reparation and the distribution of fibrillar collagens in the lateral collateral ligament epi... more The reparation and the distribution of fibrillar collagens in the lateral collateral ligament epiligament tissue may have an important role during early healing. The aim of this study was to determine the different types of fibrillar collagens synthesized in the epiligament scar throughout the initial thirty days after injury in rats. Therefore, we performed surgical transection of this ligament using rat knee model and allowed the tissue to heal spontaneously. On the eighth, sixteenth and thirtieth day after injury, the animals were sacrificed and the ligaments were examined. Our results revealed that on the eighth and sixteenth day post-injury the epiligament tissue was not completely regenerated. Immunohistochemical studies revealed localization of type I, III and V collagen in the EL substance. On the thirtieth day after injury the epiligament was similar to normal, but not fully restored. Immunohistochemical reactions for collagens type I, III and V were also positive. This study presents detailed description of the early epiligament healing process and illustrates for the first time the distribution of fibrillar collagens during epiligament healing.
Bisphosphonates are the most widely prescribed treatment for postmenopausal osteoporosis, seconda... more Bisphosphonates are the most widely prescribed treatment for postmenopausal osteoporosis, secondary osteoporosis, and male osteoporosis. Notwithstanding their high effectiveness and favorable safety profile, the adherence to bisphosphonate treatment remains low. Different treatment strategies aim to improve the clinical effectiveness of bisphosphonate therapy. This review paper assesses the clinical utility of oral intermittent risedronate in the treatment of postmenopausal osteoporosis. The new delayed-release risedronate formulation is a safer and easy to use alternative to other risedronate therapy. Oral risedronate, a potent nitrogen-containing bisphosphonate, has been extensively studied using daily regimens. A new intermittent (weekly) dosing regimen confirmed its clinical effectiveness in relation to vertebral and nonvertebral fracture prevention. The absence of significant differences in the incidence of adverse effects confirmed the favorable tolerability of the weekly dosage. In efforts to improve patient adherence to treatment, an innovative, delayed-release formulation of risedronate, which ensures adequate bioavailability of the active compound when taken with food, was introduced. The once-weekly delayed-release formulation of risedronate proved to be noninferior to the daily dosage of risedronate in terms of bone mineral density and markers of bone turnover. In addition, the incidence of new morphometric vertebral fractures was comparable in both treatment regimens. The new delayed-release formulation of risedronate showed a favorable safety profile. Delayed-release risedronate is a promising, new, effective, and convenient alternative to current bisphosphonate treatments. It appears to allow better patient adherence to antiresorptive treatment.
Background: In this study, we evaluated the changes which occurred in the epiligament, an envelop... more Background: In this study, we evaluated the changes which occurred in the epiligament, an enveloping tissue of the ligament, during the ligament healing. We assessed the association of epiligament elements that could be involved in ligament healing. Methods: Thirty-two 8-month old male Wistar rats were used in this study. In twenty-four of them the lateral collateral ligament of the knee joint was surgically transected and was allowed to heal spontaneously. The evaluation of the epiligament healing included light microscopy and transmission electron microscopy. Results: At the eight, sixteenth and thirtieth day after injury, the animals were sacrificed and the ligaments were examined. Our results revealed that on the eight and sixteenth day post-injury the epiligament tissue is not completely regenerated. Till the thirtieth day after injury the epiligament is similar to normal, but not fully restored. Conclusion: Our study offered a more complete description of the epiligament healing process and defined its important role in ligament healing. Thus, we provided a base for new strategies in ligament treatment.
During routine anatomical dissection a rare case of a flexor digitorum accessorius longus muscle ... more During routine anatomical dissection a rare case of a flexor digitorum accessorius longus muscle was observed. This muscle arose with a well-formed muscular belly from the lower part of the lateral intermuscular septum, and then passed obliquely downward and medially deep to the calcanean tendon in the canal of the flexor hallucis longus. In the sole region the aberrant muscle prolonged in a thin tendon that divided into two parts: superficial and deep. The superficial part attached to the tendon of the flexor digitorum longus for the second toe; the deep part of the tendon joined the tendon of the quadratus plantae and also an additional portion of the flexor hallucis longus tendon to the second toe. The possible clinical implications of this muscle in practical surgery and also in imaging radiology are reviewed.
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Papers by Plamen Kinov
Methods: Thirty-two 8-month old male Wistar rats were used in this study. In twenty-four of them the lateral collateral ligament of the knee joint was surgically transected and was allowed to heal spontaneously. The evaluation of the epiligament healing included light microscopy and transmission electron microscopy.
Results: At the eight, sixteenth and thirtieth day after injury, the animals were sacrificed and the ligaments were examined. Our results revealed that on the eight and sixteenth day post-injury the epiligament tissue is not completely regenerated. Till the thirtieth day after injury the epiligament is similar to normal, but not fully restored.
Conclusion: Our study offered a more complete description of the epiligament healing process and defined its important role in ligament healing. Thus, we provided a base for new strategies in ligament treatment.
Methods: Thirty-two 8-month old male Wistar rats were used in this study. In twenty-four of them the lateral collateral ligament of the knee joint was surgically transected and was allowed to heal spontaneously. The evaluation of the epiligament healing included light microscopy and transmission electron microscopy.
Results: At the eight, sixteenth and thirtieth day after injury, the animals were sacrificed and the ligaments were examined. Our results revealed that on the eight and sixteenth day post-injury the epiligament tissue is not completely regenerated. Till the thirtieth day after injury the epiligament is similar to normal, but not fully restored.
Conclusion: Our study offered a more complete description of the epiligament healing process and defined its important role in ligament healing. Thus, we provided a base for new strategies in ligament treatment.