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Three-dimensional postoperative accuracy of extra-articular forearm osteotomies using CT-scan based patient-specific surgical guides.

Vlachopoulos L, Schweizer A, Graf M, Nagy L, Fürnstahl P - BMC Musculoskelet Disord (2015)

Bottom Line: However, the difference between planned and performed reduction is difficult to assess with conventional radiographs.The technique demonstrated high accuracy in performing closing wedge (or single-cut) osteotomies.However, for opening wedge osteotomies with extensive lengthening, probably due to the fact that precise reduction was difficult to achieve or maintain, the final corrections were less accurate.

View Article: PubMed Central - PubMed

Affiliation: Computer Assisted Research and Development Group, Balgrist University Hospital, University of Zurich, Zurich, Switzerland. lvlachopoulos@card.balgrist.ch.

ABSTRACT

Background: Computer assisted corrective osteotomy of the diaphyseal forearm and the distal radius based on computer simulation and patient-specific guides has been described as a promising technique for accurate reconstruction of forearm deformities. Thereby, the intraoperative use of patient-specific drill and cutting guides facilitate the transfer of the preoperative plan to the surgery. However, the difference between planned and performed reduction is difficult to assess with conventional radiographs. The aim of this study was to evaluate the accuracy of this surgical technique based on postoperative three-dimensional (3D) computed tomography (CT) data.

Methods: Fourteen patients (mean age 23.2 (range, 12-58) years) with an extra-articular deformity of the forearm had undergone computer assisted corrective osteotomy with the healthy anatomy of the contralateral uninjured side as a reconstruction template. 3D bone surface models of the pathological and contralateral side were created from CT data for the computer simulation. Patient-specific drill and cutting guides including the preoperative planned screw direction of the angular-stable locking plates and the osteotomy planes were used for the intraoperative realization of the preoperative plan. There were seven opening wedge osteotomies and nine closing wedge (or single-cut) osteotomies performed. Eight-ten weeks postoperatively CT scans were obtained to assess bony consolidation and additionally used to generate a 3D model of the forearm. The simulated osteotomies- preoperative bone models with simulated correction - and the performed osteotomies - postoperative bone models - were analyzed for residual differences in 3D alignment.

Results: On average, a significant higher residual rotational deformity was observed in opening wedge osteotomies (8.30° ± 5.35°) compared to closing wedge osteotomies (3.47° ± 1.09°). The average residual translation was comparable small in both groups, i.e., below 1.5 mm and 1.1 mm for opening and closing wedge osteotomies, respectively.

Conclusions: The technique demonstrated high accuracy in performing closing wedge (or single-cut) osteotomies. However, for opening wedge osteotomies with extensive lengthening, probably due to the fact that precise reduction was difficult to achieve or maintain, the final corrections were less accurate.

No MeSH data available.


Related in: MedlinePlus

Postoperative 3D evaluation of the cases with highest residual error. Preoperatively planned reduction (orange and violet fragments) and postoperative result (cyan) of (a) case 10 and (b) case 11
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Fig5: Postoperative 3D evaluation of the cases with highest residual error. Preoperatively planned reduction (orange and violet fragments) and postoperative result (cyan) of (a) case 10 and (b) case 11

Mentions: Results of the preoperative planning and the postoperative accuracy evaluation are given in Table 2 and Fig. 4. On average, a significant higher (i.e., P = 0.03) difference in rotation between planned correction and postoperative result was observed in group II (8.30° ± 5.35°) compared to group I (3.47° ± 1.09°). The highest residual deformity was observed in case 10 and case 11 (Fig. 5). In these cases, also a deviation from the planned screw direction was located. For group I, the mean residual rotational deformity in sagittal, frontal, and transverse plane was 1.4° ± 0.84°, 1.56° ± 1.01°, and 2.39° ± 1.31°, respectively. For Group II, a residual rotation of 3.84° ± 4.23° in the sagittal plane, 3.97° ± 4.12° in the frontal plane, and 3.73° ± 3.88° in the transverse plane was measured. The average displacement between planned and performed reduction was between 0.5–1.48 mm and 0.94–1.04 mm for group I and group II, respectively.Fig. 4


Three-dimensional postoperative accuracy of extra-articular forearm osteotomies using CT-scan based patient-specific surgical guides.

Vlachopoulos L, Schweizer A, Graf M, Nagy L, Fürnstahl P - BMC Musculoskelet Disord (2015)

Postoperative 3D evaluation of the cases with highest residual error. Preoperatively planned reduction (orange and violet fragments) and postoperative result (cyan) of (a) case 10 and (b) case 11
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4634814&req=5

Fig5: Postoperative 3D evaluation of the cases with highest residual error. Preoperatively planned reduction (orange and violet fragments) and postoperative result (cyan) of (a) case 10 and (b) case 11
Mentions: Results of the preoperative planning and the postoperative accuracy evaluation are given in Table 2 and Fig. 4. On average, a significant higher (i.e., P = 0.03) difference in rotation between planned correction and postoperative result was observed in group II (8.30° ± 5.35°) compared to group I (3.47° ± 1.09°). The highest residual deformity was observed in case 10 and case 11 (Fig. 5). In these cases, also a deviation from the planned screw direction was located. For group I, the mean residual rotational deformity in sagittal, frontal, and transverse plane was 1.4° ± 0.84°, 1.56° ± 1.01°, and 2.39° ± 1.31°, respectively. For Group II, a residual rotation of 3.84° ± 4.23° in the sagittal plane, 3.97° ± 4.12° in the frontal plane, and 3.73° ± 3.88° in the transverse plane was measured. The average displacement between planned and performed reduction was between 0.5–1.48 mm and 0.94–1.04 mm for group I and group II, respectively.Fig. 4

Bottom Line: However, the difference between planned and performed reduction is difficult to assess with conventional radiographs.The technique demonstrated high accuracy in performing closing wedge (or single-cut) osteotomies.However, for opening wedge osteotomies with extensive lengthening, probably due to the fact that precise reduction was difficult to achieve or maintain, the final corrections were less accurate.

View Article: PubMed Central - PubMed

Affiliation: Computer Assisted Research and Development Group, Balgrist University Hospital, University of Zurich, Zurich, Switzerland. lvlachopoulos@card.balgrist.ch.

ABSTRACT

Background: Computer assisted corrective osteotomy of the diaphyseal forearm and the distal radius based on computer simulation and patient-specific guides has been described as a promising technique for accurate reconstruction of forearm deformities. Thereby, the intraoperative use of patient-specific drill and cutting guides facilitate the transfer of the preoperative plan to the surgery. However, the difference between planned and performed reduction is difficult to assess with conventional radiographs. The aim of this study was to evaluate the accuracy of this surgical technique based on postoperative three-dimensional (3D) computed tomography (CT) data.

Methods: Fourteen patients (mean age 23.2 (range, 12-58) years) with an extra-articular deformity of the forearm had undergone computer assisted corrective osteotomy with the healthy anatomy of the contralateral uninjured side as a reconstruction template. 3D bone surface models of the pathological and contralateral side were created from CT data for the computer simulation. Patient-specific drill and cutting guides including the preoperative planned screw direction of the angular-stable locking plates and the osteotomy planes were used for the intraoperative realization of the preoperative plan. There were seven opening wedge osteotomies and nine closing wedge (or single-cut) osteotomies performed. Eight-ten weeks postoperatively CT scans were obtained to assess bony consolidation and additionally used to generate a 3D model of the forearm. The simulated osteotomies- preoperative bone models with simulated correction - and the performed osteotomies - postoperative bone models - were analyzed for residual differences in 3D alignment.

Results: On average, a significant higher residual rotational deformity was observed in opening wedge osteotomies (8.30° ± 5.35°) compared to closing wedge osteotomies (3.47° ± 1.09°). The average residual translation was comparable small in both groups, i.e., below 1.5 mm and 1.1 mm for opening and closing wedge osteotomies, respectively.

Conclusions: The technique demonstrated high accuracy in performing closing wedge (or single-cut) osteotomies. However, for opening wedge osteotomies with extensive lengthening, probably due to the fact that precise reduction was difficult to achieve or maintain, the final corrections were less accurate.

No MeSH data available.


Related in: MedlinePlus