[Anatomical total shoulder replacement in glenohumeral osteoarthritis : Indications, current implants, and clinical results]

IMPLANT DESIGNS

Within the last 50 years, implants for shoulder replacement have developed rapidly. Monobloc-stems in few sizes were changed to modular implant systems that allow for an individual adaption of the stem, as well as adaption of the humeral head component according to the specific anatomic situation of the patient. Moreover, stemless und short stem implants are available, which may highly simplify primary implantation, especially in posttraumatic cases as well as in revision cases with a need for removal or change of the implants. Concerning the glenoid component, cemented PE-inlays were further modified to increase long-term survival rates. Moreover, cement-free modular "metal-backs" allow for a conversion to a reverse total shoulder arthroplasty without removal of the "metal back" component.

RESULTS

Long-term survival rates of total shoulder arthroplasties achieve comparable survival rates to knee and hip arthroplasties with good to excellent clinical long-term results. In addition to an experienced surgeon, the key to a successful surgical result is the correct and timely indication, as massive contractures of the soft tissues as well as excessive abrasion of the glenoid bone may significantly impair the functional results.

[Prevention of lateral cortex fractures in open wedge high tibial osteotomies : The anteroposterior drill hole approach]

BACKGROUND

In osteotomies with larger correction angles, the capacity for elastic deformation is frequently exceeded, resulting in plastic deformation and fracture of the opposite cortex, which may lead to subsequent loss of correction. An anteroposterior drill hole at the apex of the horizontal osteotomy (= hinge) is supposed to increase the capacity of the bony hinge for elastic deformation and ideally to prevent fractures of the opposite cortex.

MATERIALS AND METHODS

A high tibial osteotomy (HTO) using standard surgical technique was performed in 20 each of Synbones, Sawbones, and human cadaver tibial specimens. In 10 specimens per group, an additional anteroposterior hinge drilling was performed at the apex of the horizontal osteotomy. All fractures of the opposite cortex were photographically and radiographically documented. All fractures were classified according to fracture types 1-3 of the Takeuchi classification.

RESULTS

Regardless of the study group, all tibial bones with an additional hinge drilling achieved larger correction angles during the spreading of the wedge until a fracture of the opposite cortex occurred. The average correction angle of all specimens without the drill hole was 2.7°, which increased to 4.8° with the hinge drill (increase by 77.8%). In correction angles exceeding 5°, all specimen showed a hinge fracture regardless of the presence or absence of a hinge drill.

CONCLUSIONS

The hinge-protecting effect is restricted to small correction angles, i. e., to unload cartilage repair regions in the absence of severe malalignment. For the treatment of varus gonarthrosis, there is no fracture-protecting effect from a hinge drill.

[Patella position and patellofemoral osteoarthritis after unicompartmental arthroplasty]

BACKGROUND

Changes of patellar position (height, tilt, and shift) and arthritis of the patellofemoral joint might potentially influence outcome after unicompartmental knee replacement.

OBJECTIVES

The purpose of this work is to evaluate the influence of the aforementioned parameters on postoperative outcome.

METHODS

Literature analysis via PubMed.

RESULTS

A total of 12 relevant studies (three about Patellar height, two about patellar tilt and shift, seven about patellofemoral osteoarthritis) could be identified. Regarding Patellar height, two out of three studies demonstrated a postoperative decrease. With regard to patellar tilt and shift, only one study identified postoperative lateralization of the patella to be a predictor for poor outcome. The radiological appearance of arthritis of the patellofemoral joint does not significantly influence postoperative knee function except for cases where only the lateral patellar facet is affected. Anterior knee pain has no influence on clinical outcome.

CONCLUSION

Literature data do not allow for a precise statement about the possible influence of patellar position on the outcome after unicompartmental knee replacement. With proper patient selection, good results can be achieved despite patellofemoral osteoarthritis.

[Osteotomy of the greater trochanter]

The increasing number of total hip arthroplasty procedures lead to an increasing number of revision surgeries. The trochanteric osteotomy technique is an established procedure in selected cases with the necessity of extending the usual surgical approach. Trochanteric osteotomy is also successfully performed in other areas, such as trauma surgery and joint-preserving surgery (surgical dislocation). Several techniques for trochanteric osteotomy are availably employing various fixation techniques and implants. This article presents the most common trochanteric osteotomy techniques for extension of the surgical approach (the classical according to Charnley, the trochanter slide, the extended trochanteric, and the stepped osteotomy) as well as clinical results and biomechanical experiences.

Influence of the initial rupture size and tendon subregion on three-dimensional biomechanical properties of single-row and double-row rotator cuff reconstructions

PURPOSE

Influence of the initial rotator cuff tear size and of different subregions of the SSP tendon on the cyclic loading behavior of a modified single-row reconstruction compared to a suture-bridging double-row repair.

METHODS

Artificial tears (25 and 35 mm) were created in the rotator cuff of 24 human cadaver shoulders. The reconstructions were performed as a single-row repair (SR) using a modified suture configuration or a suture-bridge double-row repair (DR). Radiostereometric analysis was used under cyclic loading (50 cycles, 10–180 N, 10–250 N) to calculate cyclic displacement in three different planes (anteroposterior (x), craniocaudal (y) and mediolateral (z) level). Cyclic displacement was recorded, and differences in cyclic displacement of the anterior compared to the posterior subregions of the tendon were calculated.

RESULTS

In small-to-medium tears (25 mm) and medium-to-large tears (35 mm), significant lower cyclic displacement was seen for the SR-reconstruction compared to the DR-repair at 180 N (p ≤ 0.0001; p = 0.001) and 250 N (p = 0.001; p = 0.007) in the x-level. These results were confirmed in the y-level at 180 N (p = 0.001; p = 0.0022) and 250 N (p = 0.005; p = 0.0018). Comparison of the initial tear sizes demonstrated significant differences in cyclic displacement for the DR technique in the x-level at 180 N (p = 0.002) and 250 N (p = 0.004). Comparison of the anterior versus the posterior subregion of the tendon revealed significant lower gap formation in the posterior compared to the anterior subregions in the x-level for both tested rotator cuff repairs (p ≤ 0.05).

CONCLUSIONS

The tested single-row repair using a modified suture configuration achieved superior results in three-dimensional measurements of cyclic displacement compared to the tested double-row suture-bridge repair. The results were dependent on the initial rupture size of the rotator cuff tear. Furthermore, significant differences were found between tendon subregions of the rotator cuff with significantly higher gap formation for the anterior compared to the posterior subregions.

Static rotational and sagittal knee laxity measurements after reconstruction of the anterior cruciate ligament

PURPOSE

The goal of the present study was to evaluate static anteroposterior and rotational knee laxity after ACL reconstructions with two noninvasive measurement devices by comparing the measured results of the operated with the contralateral healthy knees of the patients.

METHODS

Fifty-two consecutive patients were reviewed after isolated single-bundle transtibial ACL reconstruction using a BPTB graft. At a mean follow-up of 27 months, sagittal AP laxity was tested using a noninvasive knee measurement system (Genourob) with an applied pressure of 67 N, 89 N and 134 N. Rotational laxity was measured using a noninvasive rotational knee laxity device (Rotameter) with an applied torque of 5, 8 and 10 Nm. The results were compared with the measurements of the patients' healthy contralateral knees. Tegner, Lysholm and IKDC score were used in order to evaluate the clinical outcome.

RESULTS

Pivot shift was negative (33) or glide (16) in 49 patients with 12 of 16 (75%) patients having also a pivot glide on the healthy contralateral side; Lachman tests were negative in 50 cases. Subjective assessment of the IKDC score was classified according to category A in 44 patients, B in 5 patients and C in 3 patients. Mean Lysholm score was 94.5 ± 9.5, median Tegner score was 7 (3-9) preoperative and 6 (3-9) at follow-up (n.s.). Anteroposterior knee laxity measurements revealed mean side-to-side differences of 0.6-1.3 mm (P < 0.0001). Rotational laxity measurements revealed no statistical significant differences between the operated and the contralateral knee (n.s.). The measured differences in the entire rotational range varied from 0.2° to 1° depending on the applied torque. In those 3 patients with a positive pivot shift, differences in the entire rotational range of 4.5° at 5 N, 4.6° at 8 N and 4.1° at 10 N were found.

CONCLUSION

Static knee laxity was quantified after ACL surgery using the introduced noninvasive measurement systems by comparing the measured results of the operated with the contralateral healthy knees. Significant differences were found in AP laxity although they were defined as clinically successful according to the IKDC classification. No significant differences were found in rotational knee laxity measurements. Therefore, the used noninvasive masurement devices might offer a high potential for objective quality control in knee ligament injuries and their treatment.

LEVEL OF EVIDENCE

Retrospective case series, Level IV.

Arthroscopic rotator cuff repair using a single-row of triple-loaded suture anchors with a modified suture configuration

Achieving an adequate restoration of the muscle-tendon-bone unit and the anatomical footprint is essential for a successful outcome in open and arthroscopic rotator cuff repair. The described suture grasping technique using triple-loaded suture anchors might combine high initial fixation strength with good footprint coverage. It describes two mattress' stitches medial at the articular margin of the tendon. Additionally, a third mattress stitch is performed laterally to increase footprint contact and avoid dog-ear deformity. The triple-mattress repair is easy to perform and might be a good alternative in either arthroscopic or open rotator cuff repair.

Radiographic guided drilling of bony tibial tunnels for fixation of meniscus transplants using percentage references

The objective of our investigation was to evaluate the precision of radiographic-guided tibial tunnel drilling for anatomical anchoring of meniscus transplants at the tibial insertion areas. In 20 cadaveric proximal tibiae, the meniscal insertions were dissected and their circumferences outlined. Standardized photographs of the tibial plateau were obtained. Applying established percentage values for radiographic determination of the meniscus insertion midpoints, tibial tunnels were drilled using a standard ACL-guide. Guide positioning was performed by using the midpoints as determined on standard AP and lateral radiographs. After tibial tunnel drilling, a second set of standardized photographs of the tibial plateau was obtained. Digital imaging permitted the superposition of pre- and postoperative images. Overlapping between the anatomical insertion areas and the tibial tunnel exit was determined, as well as the distance between the borders of the insertion areas and the tunnel exit. Insertion area and tunnel exit showed a mean overlapping of 59.8 ± 34.8% (anterior horn), respectively 62.4 ± 32.0% (posterior horn) for the lateral meniscus and of 88.4 ± 15.5% (anterior horn), respectively 60.3 ± 31.6% (posterior horn) for the medial meniscus. Mean distance between the borders of insertion area and tunnel exit was 2.0 ± 1.5 mm (anterior horn), respectively 2.0 ± 1.7 mm (posterior horn) for the lateral meniscus and 0.9 ± 0.9 mm (anterior horn), respectively 2.1 ± 1.4 mm (posterior horn) for the medial meniscus. Thus, a precise drilling of tibial tunnels at the anatomical insertions of the menisci can be obtained by positioning a standard ACL-guide under radiographic control in a cadaver setting. In advanced day-by-day clinic, this knowledge could facilitate the surgical technique for anatomical fixation of lateral and medial meniscus transplants.

[Muscle injuries: diagnostics and treatments]

Muscle injuries are common in sports. They are usually caused by either acute (mostly eccentric mechanisms) or chronic overloading with a lack of muscle coordination. They present in clinical practice as bruises and muscle sprains. Due to the rigours of a modern society and the high economic cost of time off work, an effective treatment needs to be employed. The key to an optimised therapy rests in the appropriate timing between immobilisation and mobilisation. The interval to muscle repair might be shortened by certain adjuvant therapies. In doing so, it is important that no physiological phases of wound healing are overlooked. Muscle healing can be accelerated by externally induced higher metabolic turnover. Surgical therapy is sometimes necessary in selected cases and in serious injuries.

[Complications with all-inside devices used in reconstructive meniscal surgery]

All-inside devices have become increasingly popular in reconstructive meniscal surgery since their introduction at the beginning of the 1990s. Although the latest clinical investigations show better results for conventional suture techniques, meniscal devices are an important alternative because of the low risk of neurovascular injury and the easy handling of the instruments. Over the years, many reports on specific complications related to all-inside devices have been published. Especially chondral injuries, implant loosening, device migration and capsular or neural irritations have been described. Furthermore, some authors reported on foreign body reactions and cystic granulomas after the use of meniscal fixation devices. However, there is no evidence for a higher infection rate or for specific infections after the use of intra-articular techniques. Clinical reports on complications along with biomechanical studies on meniscal repair devices have led to the enhancement of all-inside techniques through substantial modifications of established products as well as to the development of new implants. After reviewing the latest literature, the complication rate seems to be decreasing. In many ways, all-inside devices are an interesting alternative to conventional suture techniques. A precise knowledge of their potential complications and the pitfalls during surgery however is crucial to make a risk evaluation in the choice of the right technique for meniscal reconstruction.

[Osteonecrosis in the postarthroscopic knee]

Osteonecrosis of the knee is a rare complication following arthroscopic surgery. Little is known about its etiology. The most important differential diagnosis is preexisting and undiagnosed early-stage spontaneous osteonecrosis of the knee. Medicolegally, arthroscopic surgery could be wrongly regarded as the primary cause for postarthroscopic osteonecrosis. Orthopedic surgeons need to be aware of the diagnostic pitfalls in differentiating between these entities. We suggest that the descriptive term "osteonecrosis in the postoperative knee" should be used rather than the captious term "postarthroscopic osteonecrosis."

Influence of deposit stage and failed ESWT on the surgical results of arthroscopic treatment of calcifying tendonitis of the shoulder

The purpose of the present study is the evaluation of a possible influence of the preoperative deposit stage, the postoperative deposit elimination and failed preoperative extracorporeal shockwave therapy on the surgical outcome of arthroscopic treatment of tendinosis calcarea. From 1997 to 2004, 65 patients underwent arthroscopic resection of calcific deposits of the shoulder after failed conservative treatment. Patients with rotator cuff tears, major cartilage damage, or previous surgery were excluded. Out of 50 patients 45 (17 men, 28 women) that could be contacted with a mean age of 49 +/- 8 years could be followed-up with a mean of 36 months (14-89) after surgery. A total of 24 patients (53.3%) underwent preoperative extracorporeal shock-wave therapy (ESWT). For the clinical evaluation the Constant and Murley Score, the Simple Shoulder Test, the Western Ontario Rotator Cuff Index (WORC) and visual analog scales for pain, function and satisfaction were used. For the radiological evaluation, the classifications according to Gaertner and Bosworth were used. Statistical analysis was done with the Wilcoxon test, the Mann-Whitney test and ANOVA. The Constant and Murley Score improved significantly from preoperative 63.5 +/- 11.4 to postoperative 93.9 +/- 9.9 points (P < .0001) at follow-up, the Simple Shoulder Test from 1.7 +/- 2 to 9.9 +/- 2.8 points (P < .0001), the WORC score from 1,591.2 +/- 337.4 to 345.4 +/- 392 points (P < .0001). The visual analog scales for pain, function and patient satisfaction also significantly improved (P < .0001). Preoperative radiological evaluation according to the Gaertner classification revealed 37 type I deposits, 6 type II and 2 type III deposits; postoperative no calcific deposits were seen in 37 patients, 6 type I and 2 type III deposits. According to the Bosworth classification 13 type I, 19 type II and 13 type III deposits were seen preoperatively. Postoperative X-rays showed 6 type I and 1 type II and III deposits. There was no significant correlation of the clinical results with the pre- or postoperative findings. The 24 patients who underwent ESWT before surgery did not show significantly better results than patients without ESWT. In conclusion, arthroscopic removal of calcific deposits of the shoulder shows good clinical results for pain reduction, shoulder function and patient satisfaction. The type of calcific deposit and the preoperative treatment of the shoulder with ESWT did not have any significant impact on the postoperative results.