Marco Bigoni

Dual X-ray absorptiometry for the evaluation of bone density from the proximal femur after total hip arthroplasty: Analysis protocols and reproducibility

SummaryDual X-ray absorptiometry (DXA) instruments are now able to evaluate bone mineral density (BMD) of bone surrounding metal implants. The assessment of BMD around prosthetic components could provide additional information for the follow-up of total hip arthroplasty (THA). In this study, we evaluated the potential application of DXA in the field of THA. BMD was measured in the proximal femur of both THA and THA-free sides in 14 postmenopausal women 6–18 months after THA. The explored segment was divided into seven zones as proposed by Gruen et al. [18]. The precision error of BMD measurements ranged from 1.8 to 6.8% on the THA side and from 1.1 to 2% to the THA-free side. The reduction of BMD of the THA versus the THA-free side was significant in all seven zones (P < 0.01, t-test for paired data). These results showed significant differences in BMD around femoral components of THA with respect to contralateral healthy side, and demonstrate the sensitivity of DXA for detecting these changes.

Periprosthetic bone density around fully hydroxyapatite coated femoral stem

In this study, periprosthetic bone mineral density was measured at scheduled time intervals after surgery by dual energy xray absorptiometry in 21 patients to assess the history of bone density redistribution after femoral stem insertion. Measurements of changes in bone density with time were obtained for the regions of the greater trochanter, the lateral cortex, the tip, the medial cortex, and the calcar. In all regions, bone density decreased during the first 3 months after surgery; this was followed by a prolonged period of 18 to 30 months of bone gain, a subsequent period of steady state, and the final resumption of bone aging processes after the third postoperative year. The greatest loss was observed in the calcar region after 6 months (greater than 50%). The characteristic pattern of time related bone density changes obtained in this study may make it possible to compare other pathologic, design, or stiffness related patterns. This could have clinical relevance in the early diagnosis of pathologic processes and as a means of evaluating prosthetic designs.

Pre- and postoperative intra-articular analgesia for arthroscopic surgery of the knee and arthroscopy-assisted anterior cruciate ligament reconstruction A double-blind randomized, prospective study

Abstract We tested the effectiveness of different intra-articular analgesics and of pre-emptive intra-articular analgesia for arthroscopy-assisted anterior cruciate ligament reconstruction (ACLR) and for operative knee arthroscopy. Eighty-two patients underwent operative knee arthroscopy under selective subarachnoid anaesthesia (group A), and 60 patients underwent arthroscopy-assisted ACLR under general anaesthesia (group B). Patients were randomly assigned to intra-articular analgesic treatment as follows. Group A: 1, morphine 2 mg; 2, preoperative morphine 2 mg; 3, morphine 5 mg; 4, preoperative morphine 5 mg; 5, bupivacaine 0.25% 20 ml; 6, bupivacaine 0.25% 20 ml + morphine 2 mg; 7, saline solution 20 ml. Group B: 1, morphine 2 mg; 2, morphine 5 mg; 3, preoperative morphine 5 mg; 4, bupivacaine 0.25% 20 ml; 5, bupivacaine 0.25% 20 ml + morphine 2 mg; 6, saline solution 20 ml. All opioids were diluted in 20 ml of saline solution. After postoperative administration the tourniquet was left in place for 10 min. After preoperative administration the intra-articular surgical procedure was delayed for about 5–10 min. In the postoperative period we recorded: total consumption of ketoprofen given i.v. on demand as rescue analgesic treatment; pain scores before surgery and at 1st, 3rd, 6th, 12th and 24th h; occurrence of local anaesthetic or opioid side-effects. Group A (operative knee arthroscopy): all morphine groups (A1, A2, A3, A4) and the bupivacaine group (A5) did not require ketoprofen postoperatively (P < 0.01 vs both groups A6 and A7). Pain scores did not differ significantly among groups. The percentage of patients reporting higher pain scores than before surgery was larger in control group A7 and in bupivacaine groups A5, A6 (83%, 40%, 60%, respectively) and lower in morphine groups A1, A2, A3, A4 (25%, 16%, 27%, 23%, respectively). Group B (ACLR): total consumption of ketoprofen was lowest in groups B2 and B3 (P < 0.001 vs all other treatments and vs control group). The percentage of patients who did not require any rescue analgesic was 60% in group B3, 50% in group B2, 32% in group B5 and 0% in all other groups. No-side effects occurred in any patient. Intra-articular analgesia is safe and effective for arthroscopic knee surgery. Morphine provides a better pain control both in operative knee arthroscopy patients and in ACLR. A 2 mg dose is adequate for operative knee arthroscopy but not for ACLR, where higher dosages are required (5 mg). Pre-emptive intra-articular morphine provides better analgesia than postoperative administration.

Long-term results of the Leeds-Keio anterior cruciate ligament reconstruction.

This paper discusses the long-term results of the anterior cruciate ligament (ACL) reconstruction with the Leeds-Keio (LK) prosthetic ligament. For this type of reconstruction we used arthrotomy and an arthroscopy-assisted technique. The fixation was obtained with two bone plugs, and the distal portion was also attached with a staple. A postoperative protocol was used with a progressive range of motion and weight bearing after 50 days. We performed 50 LK operations in professional and amateur athletes aged 17–39 years with an isolated anterior instability. We reviewed at follow-up (5–7 years) 37 patients; 8 were lost, and 5 had a subsequent failure. At the Lysholm score the patients were classified: 19 excellent, 13 good, 3 fair, and 2 poor. At the IKDC grading the patients were classified as follows: 2 class A, 22 B, 8 C, and 5 D. The Lachman test was 1+ in 15 patients, 2+ in 7, 3+ in 2, and negative in 13: pivot shift was 1+ in 9, 2+ in 7, 3+ in 2, and negative in 25. Results of the KT 1000 test at 30 Ib side to side was <3 mm in 23 patients, 3–5 mm in 6, 6–10 mm in 6, and >10 mm in 2. In view of the results observed and the progressive deterioration over the years, this procedure should no longer be performed as an ACL substitute.

BONE ASSESSMENT AFTER TOTAL KNEE ARTHROPLASTY BY DUAL-ENERGY X-RAY ABSORPTIOMETRY : ANALYSIS PROTOCOL AND REPRODUCIBILITY

Abstract. Bone quality is important for the success of joint prostheses implantation, and the assessment of bone density after total knee arthroplasty by means of dual-energy X-ray absorptiometry may be useful for monitoring implant stability. The aim of this study is to suggest a validated analysis protocol for the assessment of bone status after total knee arthroplasty. A dedicated densitometric analysis protocol of five regions of interest was designed, and 10 subjects who had received an uncemented knee prosthesis (8 females and 2 males, aged 55–74 years) underwent three consecutive scans in posteroanterior and lateral projections, with repositioning after each scan to test the suitability and reproducibility of the protocol. The reproducibility of the measurement of bone mineral content and density in the femoral and tibial regions ranged, respectively, from 2.1% to 4.1%, from 0.9% to 2.6% for the posteroanterior scans, and from 2.7% to 5.6% and from 2.3% to 4.7% for the lateral scans, depending on the considered region. Our results confirm that the suggested protocol allows precise assessment of bone mineral content and density, and that dual-energy X-ray absorptiometry is reliable for the evaluation of bone mass around prosthetic implants.

Graft-tunnel mismatch in endoscopic anterior cruciate ligament reconstruction: Intraoperative and cadaver measurement of the intra-articular graft length and the length of the patellar tendon

Abstract The results of a study conducted on 50 knees endoscopically reconstructed for an anterior cruciate ligament (ACL) lesion with a free bone-patellar tendon-bone graft and 9 cadaver knees are reported. The mean lengths of the patellar tendon (45.48 ± 4.71 mm) and intra-articular ACL graft (20.44 ± 1.98 mm) were measured in the operated knees. The mean length of the tibial bone tunnel (51.62 ± 2.60 mm) was also measured with a tibial guide at 55°. No statistically significant correlation was found between these three measurements. The length of the patellar tendon was weakly correlated with body height. Measurement of the tibial tunnel on the cadaver knees with increasing degrees of inclination revealed a mean length increase of 0.68 mm per degree (confidence limits: 0.49–0.86). Comparison between the tunnel lengths obtained with the guide and those measured with a Kirschner wire showed a mean difference of 2.3 mm. It is thus desirable to make the tunnel about 53 mm long to ensure excellent fixation of a 28 mm bone block with a 25 mm interference screw. Correct measurement of the anatomical structures involved is in any event an essential requirement for proper execution of the surgical technique.

Effects of physical training of the dominant arm on ipsilateral radial artery distensibility and structure

Background Exercise training induces cardiovascular changes that are both generalized and restricted to the microcirculation of the tissues more actively involved in the exercise itself. Whether the local effect of exercise extends to larger arteries is unknown, however. Methods In the right and left upper limb of 17 right-handed subjects performing an asymmetric training of the upper limbs (hammer throwers and baseball players) and 16 age-matched sedentary controls, we continuously measured radial artery diameter, distensibility and wall thickness by an echotracking and a beat-to-beat finger blood pressure device. Arterial distensibility was calculated by the arctangent model of Langewouters and expressed as continuous values from diastolic to systolic blood pressure. Measurements were made: (1) in baseline conditions; (2) after release from prolonged proximal ischaemia; and (3) after an increase in radial artery blood flow caused by a short (4 min) distal ischaemia to determine the endothelial involvement in the training-induced change in arterial distensibility. Results In athletes the radial artery distensibility was markedly greater in the right than in the left arm, the latter showing values slightly greater than those seen in the two arms of sedentary subjects. In both arms and groups radial artery distensibility increased markedly after prolonged ischaemia, the between arm and group differences being preserved, however. The radial artery response to distal short ischaemia was, on the other hand, similar in the two arms of the athletes, although greater in these subjects than in the sedentary ones. Radial artery wall thickness was greater in the trained than in the untrained arm of athletes, both values being greater than in sedentary subjects. Conclusions Asymmetrical training of the upper limbs is accompanied by a greater distensibility of the middle-sized arteries of the more trained side. This is not associated with asymmetrical changes in endothelial structure or function. It is associated with a greater wall thickness in the trained side, suggesting that, at least in part, a training-induced asymmetrical change in wall structure (possibly with a predominance of more distensible tissues such as elastine and smooth muscle) is responsible.

Effects of Prolonged Immobilization of the Limb on Radial Artery Mechanical Properties

Physical training is associated with an increase in arterial distensibility. Whether the effect of training on this variable is evident also for ordinary levels of exercise or no exercise is unknown, however. We have addressed this issue by investigating the effect on radial artery distensibility of prolonged monolateral immobilization of the ipsilateral limb versus the following resumption of normal mobility. We studied 7 normotensive subjects (age, 25.4+/-3.0 years; systolic/diastolic blood pressure, 119+/-9/68+/-6 mm Hg, mean+/-SE) in whom 1 limb had been immobilized for 30 days in plaster because of a fracture of the elbow. At both the day after plaster removal and after 45 days of rehabilitation, radial artery distensibility was evaluated by an echo-tracking device (NIUS-02), which allows arterial diameter to be measured noninvasively and continuously over all pressures from diastole to systole (finger monitoring), with the distensibility values being continuously derived from the Langewouters formula. In both instances, the contralateral arm was used as control. Immediately after removal of the plaster, radial artery distensibility was markedly less in the previously immobilized and fractured limb compared with the contralateral limb (0.4+/-0.1 versus 0.8+/-0.1, 1/mm Hg 10(-3), P<0.05). After rehabilitation, the distensibility of the radial artery was markedly increased in the previously fractured limb (0.65+/-0.1 1/mm Hg 10(-3), P<0.05), whereas no change was seen in the contralateral limb. Thus, complete interruption of physical activity is associated with a marked reduction of arterial distensibility, indicating that even an ordinary level of activity plays a major role in modulation of arterial mechanical properties.

Gotfried percutaneous compression plating (PCCP) versus dynamic hip screw (DHS) in hip fractures: blood loss and 1-year mortality

BackgroundIntertrochanteric fractures are among the most common fracture in elderly and are correlated with an average 1-year mortality of 25xa0%. Increased mortality after hip fracture could be related to blood loss and comorbidities.AimsWe compared two groups of patients treated with percutaneous compression plating (PCCP) and dynamic hip screw (DHS) with the hypothesis that treatment with PCCP can reduce blood loss and 1-year mortality. We furthermore investigated the role of several surgical-related and patient-related factors on mortality of all the enrolled patients.MethodsWe performed a comparative retrospective study of 280 patients with type 31A1 or 31A2 hip fractures treated in our department from January 2004 to May 2008. Exclusion criteria were age <60xa0years, multiple injuries and pathological fractures. A total of 194 patients were treated with DHS, and 86 patients were treated with PCCP.ResultsNo statistical differences were found in term of blood loss, blood transfusion and 1-year mortality between the two groups, whereas we found a significant incidence of gender, age, American Society of Anaesthesiologists score and preoperative haemoglobin on mortality.DiscussionBoth plates seem to be comparable in terms of blood loss and blood transfusion rate, and mortality was rather correlated with some patient-related factors reflecting the global health status.ConclusionEmerging mortality in this kind of patient should encourage us to improve preventative orthogeriatric health care.

Changes in bone mineral density following total knee arthroplasty: a 1-year follow-up study by dual energy X-ray absorptiometry

Abstract The assessment of bone density by means of dual energy Xray absorptiometry is a valid option for monitoring bone changes. In this study, time-related bone changes after total knee arthroplasty implantation were assessed in eight postmenopausal women (aged 62–72 years) up to one year from surgery. The pattern of bone changes followed a well-known design: an initial phase of accelerated bone loss and a subsequent phase of partial bone recovery. The greatest bone loss was observed at 2 months after surgery: 5.0% for the whole periprosthetic bone in the AP projection and 11.5% for the bone in the LL projection. In the following ten months the bone loss in the AP projection was completely recovered while the periprosthetic bone evaluated in the LL projection showed a residual bone loss of 9.0%. At 12 months from surgery, the distal femur in LL projection showed the greatest bone loss: 20.0% for the anterior region of interest and 17.0% for the posterior one. A significant correlation was found between the maximum postoperative bone loss and the residual bone loss at 12 months. These results suggest that pharmacological and rehabilitative strategies may be useful for the conservation of bone stock.